Luminous Landscape Forum

Raw & Post Processing, Printing => Other Raw Converters => Topic started by: Fine_Art on January 13, 2013, 03:27:13 pm

Title: RAW Conversion Snake Oil
Post by: Fine_Art on January 13, 2013, 03:27:13 pm
Yesterday I stumbled upon a new raw converter. The default conversion looked pretty good.

I abused it relative to what the manufacturer expected by moving all the NR sliders to zero. I expected this to show a 'raw' RAW. I ended up with a mess of color blotches. This made me realize how much of the raw conversion is interpretation. I went for a 'real raw' RAW with the purest software I know. It was developed by a mathematician at a US university for amateur astronomy. What I found is the noise in a high ISO shot is nowhere near as objectionable as it normally appears in raw conversions. The raw converters themselves actually create the ugliness by trying to smooth away the noise! Yes, even chrominance noise looks fine when it is even at the pixel level. It is when it is grouped into small areas that it looks like hell. I'm not saying you dont want to remove it, I am saying if you go to print, pixel level color noise will vanish. Even the softness of the file is largely CREATED by trying to smooth colors away.

Attached is a real raw RAW.

I have added gamma 2.2, White balance yellow +2000 vs blue (it was a sun setting so a more golden hr look is correct)

I have also used the software to split each color from luminance. Note the heavy noise in red and green. Of course I then had the bright idea to do various types of smoothing on those channels so I could recombine with noise wiped out!

Of course I end up exactly where the RAW converters do with a soft looking image! Not only that but the smoothing of color noise per channel did not evenly line up. Surprise surprise I end up with the small color blotches we see on our raw conversions before further NR.

What am I doing here? I found I was pulling back the curtain on the Wizard of Oz. At the pixel level the RAW tif (yes RAWS are compressed tifs) can only have a luminance value and a color value. All the countless sliders you see in software con only manipulate those things. Keep that in mind.



Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 13, 2013, 03:33:21 pm
Here is the separated color channels.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 13, 2013, 03:38:14 pm
Then a recombined smoothed file. Does the mush of the detail look like what drives everyone to buy more expensive lenses? It is created by the software. Look at the detail in the original RAW above.

The multiple posts are from the attachment size limit.
Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 13, 2013, 04:30:09 pm
What am I doing here?

Chasing shadows of your tail?
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 13, 2013, 05:16:32 pm
Chasing shadows of your tail?

You work for a RAW software provider?
Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 13, 2013, 05:20:43 pm
You work for a RAW software provider?

Nope.
Title: Re: RAW Conversion Snake Oil
Post by: woos on January 13, 2013, 05:22:53 pm
It's rather true lol.  Open up raw therapee and zero everything out, turn all NR off, etc.  Note what the noise looks like.  Then do the same in camera raw or lightroom.  Hmmmm...^_^  Now, floating point may be overkill, but on the other hand, maybe not. lol
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 13, 2013, 05:24:42 pm
Nope.

In this other post you seem to be trying to make a mythology for a product.

Lightroom is on v4.x

Lightroom is beyond impressive to me ... it the single most impressive pieces of "consumer" software I have ever seen.  The ambition and "game-changing" nature of the project is inspiring to me as someone who lives in "legacy" world trying to innovate.

The story of Lightroom is a an amazing story.
Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 13, 2013, 05:36:03 pm
In this other post you seem to be trying to make a mythology for a product.


You are accusing me of what?  Pretending to admire the company as some kind of paid shill?

If so, you've lost your mind.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 13, 2013, 05:38:10 pm
You are accusing me of what?  Pretending to admire the company as some kind of paid shill?

If so, you've lost your mind.

I asked if you work for a related company. Your post did seem to gush excessively. Keyword asked.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 13, 2013, 09:28:52 pm
After using various noise and sharpening techniques I have a reasonable 50% crop out of the high ISO file. It has less sharpness and less noise that the RAW. If you have a very pure raw converter and plenty of pixels the file will look as good as a heavily processed file. "You can't turn a sow's ear into a silk purse." I could process this file with "Capture sharpening" techniques. It seems a joke knowing the sharpness of the original RAW.

Of course the real picture is a 5 wide x 2 high pano at ISO 100 not this camera test file.

Title: Re: RAW Conversion Snake Oil
Post by: Tim Lookingbill on January 13, 2013, 11:01:11 pm
Quote
What am I doing here? I found I was pulling back the curtain on the Wizard of Oz. At the pixel level the RAW tif (yes RAWS are compressed tifs) can only have a luminance value and a color value. All the countless sliders you see in software con only manipulate those things. Keep that in mind.

Keep this in mind. It's called a converter for a reason. It converts data from one state to another. It's all raster data. You want to call it a tiff? Call it tiff. It's pointless because a tiff is nothing but a raster mapping of data. Your OS video system's frame buffer is a raster of data as well. Do you want to call your video card a raster tiff generator? What's the point?

You know what raster means, right? You have an X/Y table mapping within a 2:3/3:4 ratio rectangle of every tiny square pixel of various luminance, the variation determined by the RGGB filtering of photons collected to create an electrical charge. That charge is assigned a voltage measurement. IT'S NOT EVEN A SQUARE PIXEL OF COLOR at this stage. A/D converter takes those charges that represent a luminance level (some of those are clumps of noise) and converts it to 1's and 0's where IT'S STILL NOT A PIXEL OR TIFF.

It's all interpreted by software! You are looking at a concoction of software that happens to generate an image that pleases you. You've just decided to pick what stage of interpretation is the most true according to what you see on your display.

That texture of noise I see in your first sample close up crop I've seen duplicated in ACR's Grain panel just by twiddling sliders long enough to find it.
Title: Re: RAW Conversion Snake Oil
Post by: Tim Lookingbill on January 13, 2013, 11:19:20 pm
There's another thing about ACR compared to your sample image in that ACR/LR's color engine and tools that act on the gradation of the interpreted raster data offer better color grading and variance that optically delivers more pleasing color.


I've seen this nuance in color gradation which to pull this off I'm assuming requires very sophisticated algorithms engineered not only in the color engine and the tools that act on each pixel but also in how it integrates with my OS video system's rasterized frame buffer and color managed previews that maps those color edits very smoothly.

What I see in your sample image is a lot of monotone/monochrome color gradation that effectively squelches the amount of color detail I know is in that type of scene. It looks very sharp but I know sawgrass has far more variation of beige's, browns and yellows I don't see in that sample. I've seen other Raw converters render color similarly to get that very sharp look but at the sacrifice of color detail which is inextricably tied to color noise especially in under exposed shots or shot with very little light like your sample.
Title: Re: RAW Conversion Snake Oil
Post by: Vladimirovich on January 13, 2013, 11:25:38 pm
What am I doing here?
repeating many posting on the same subject here from the days past...
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 14, 2013, 01:00:26 am
repeating many posting on the same subject here from the days past...

That would not surprise me.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 14, 2013, 01:18:41 am
There's another thing about ACR compared to your sample image in that ACR/LR's color engine and tools that act on the gradation of the interpreted raster data offer better color grading and variance that optically delivers more pleasing color.


I've seen this nuance in color gradation which to pull this off I'm assuming requires very sophisticated algorithms engineered not only in the color engine and the tools that act on each pixel but also in how it integrates with my OS video system's rasterized frame buffer and color managed previews that maps those color edits very smoothly.

What I see in your sample image is a lot of monotone/monochrome color gradation that effectively squelches the amount of color detail I know is in that type of scene. It looks very sharp but I know sawgrass has far more variation of beige's, browns and yellows I don't see in that sample. I've seen other Raw converters render color similarly to get that very sharp look but at the sacrifice of color detail which is inextricably tied to color noise especially in under exposed shots or shot with very little light like your sample.

I did not mention a particular brand of software. I have noticed the issue I am talking about with several packages not the ACR/LR some want to champion.

There are several features in a raw converter that a straight conversion will fail on. Color fringing on highlights. These are well controlled in LR, RT and several other packages. Distortion correction. Vignetting. Any algorithms that manipulate groups of pixels for whatever reason.

Back to what I was talking about - clumps of colored pixels are purely a failure of the de-bayering. You either leave an area showing colors at individual pixels which zoomed out blend to the proper color or you have a color at the pixel level that is really in the scene. Clumps of red and green are not in the scene.

Doing a straight conversion of a low ISO image yields worse results than the various converter packages. On that they are fine. This is a problem specific to handling high ISO noise by blending areas.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 14, 2013, 01:34:35 am
I looked up your sawgrass, it is not here.

That is either hay stalks or wheat stalks. And by stalks I mean it has been combine harvested.

Here is a wiki picture of hay.
(http://upload.wikimedia.org/wikipedia/commons/f/fd/Round_hay_bale%2C_partially_eaten.jpg)

Any variation you can see up close will not show up at 1/2 a km. So no magic software is going to find it.
Title: Re: RAW Conversion Snake Oil
Post by: Tim Lookingbill on January 14, 2013, 02:57:52 am
The cropped close up image you posted has a ton of clumped color noise as well as limited color detail. It's not a pleasing looking image viewing at 100%. The lack of color detail gradations even shows in the separate RGB channel samples.

I'ld have to say that is a poor sample image to be demonstrating a converter's handling of noise. Or I'm at a loss on what you're trying to show us with that image. I don't see anything revealing in that image that is useable information.

I used the term "sawgrass" to describe the short grass I see covering the rolling plains. It's all one monochrome color.

I can tell you I've gotten better looking images with regard to noise and detail appearance shooting at 1/1250 sec., f/8, ISO 800 (the exposure of your posted image). That exposure indicates there was quite a bit of light that should've given less noise at ISO 800 than what's seen in your image sample.
Title: Re: RAW Conversion Snake Oil
Post by: Tim Lookingbill on January 14, 2013, 03:12:08 am
Just found out it's a Sony SLT A55v using a 16MP APS-C sensor. That explains the image quality. ImagesPlus is the converter used.

Their website indicates its use in astronomy.

 
Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 14, 2013, 06:51:51 am
At the pixel level the RAW tif (yes RAWS are compressed tifs) can only have a luminance value and a color value. All the countless sliders you see in software con only manipulate those things. Keep that in mind.

Can you please illuminate the consequence of this conclusion?

I'm not sure I understand what you are trying to share with us here ...
Title: Re: RAW Conversion Snake Oil
Post by: digitaldog on January 14, 2013, 10:21:55 am
I'm not sure I understand what you are trying to share with us here ...

My interpretation is: raw is raw and if you could look at it, it would look ugly and all raw converters affect the raw differently, like a piece of digital clay, you can end up with a lovely vase or an ugly ashtray? Nothing earth startling for many of us.
Title: Re: RAW Conversion Snake Oil
Post by: Tim Lookingbill on January 14, 2013, 11:18:12 am
My interpretation is: raw is raw and if you could look at it, it would look ugly and all raw converters affect the raw differently, like a piece of digital clay, you can end up with a lovely vase or an ugly ashtray? Nothing earth startling for many of us.

That's what I suspected on first read of the OP's topic, but what I couldn't figure out is how this information is beneficial to photographers. I can see its importance to astronomers who want data captured millions of miles away unfettered by software.

I realize CS3 ACR vs CS5 major changes to default noise suppression was employed that allowed more refined noise to appear when sharpening that basically turned CS3's mottled clay like texture to detail viewed at 100% (a few users complained about, me included) into a more evenly distributed fine dithered pattern.

Of course as I've admitted in the past neither of these two texture appearances can be seen in a print but did see how it bothered pixel peepers viewing their images at 100%.
Title: Re: RAW Conversion Snake Oil
Post by: ErikKaffehr on January 14, 2013, 12:44:18 pm
Hi,

I admittedly never printed this, but I still think the progress is significant:

(http://echophoto.dnsalias.net/ekr/images/PVCompare/PV_2003_vs_2010_ISO6400.jpg)
The image above demonstrates noise reduction in LR2 vs LR3

With LR4 we got perspective correction, lens profiles etc. But the great news is tone mapping, even if it subtle.

Best regards
Erik


That's what I suspected on first read of the OP's topic, but what I couldn't figure out is how this information is beneficial to photographers. I can see its importance to astronomers who want data captured millions of miles away unfettered by software.

I realize CS3 ACR vs CS5 major changes to default noise suppression was employed that allowed more refined noise to appear when sharpening that basically turned CS3's mottled clay like texture to detail viewed at 100% (a few users complained about, me included) into a more evenly distributed fine dithered pattern.

Of course as I've admitted in the past neither of these two texture appearances can be seen in a print but did see how it bothered pixel peepers viewing their images at 100%.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 14, 2013, 12:57:01 pm
Its certainly a lot better. The mild color banding should not be there at all. A noise app would then remove it by further smearing the detail. Then people want more "capture sharpening".
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 14, 2013, 01:04:34 pm
Just found out it's a Sony SLT A55v using a 16MP APS-C sensor. That explains the image quality. ImagesPlus is the converter used.

Their website indicates its use in astronomy.

 

I did not mention the software as the thread is not about promoting a piece of software. It deserves promotion elsewhere.

We are not talking about the hay image from wiki.

The thing about that software is it does a minimal conversion then gives you a variety of algorithms with their real names. It doesn't try to pretend it created magic with terms like "recovery".

Anyway your post is irrelevant to the discussion. The shot is with a 100 macro (150mm equivalent) that is why it is crisp at the pixel level until a converter smears it all out.
Title: Re: RAW Conversion Snake Oil
Post by: digitaldog on January 14, 2013, 01:35:34 pm
It doesn't try to pretend it created magic with terms like "recovery".

Pretend how? The data was there, a slider with a name showed it once set as desired.
Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 14, 2013, 01:37:41 pm
It doesn't try to pretend it created magic with terms like "recovery".

I don't see all this deception to which you refer again and again.

Are you REALLY, TRULY disappointed with results you can achieve with state-of-the-art cameras with Bayer CFAs and commercial RAW converters?

I'm not.

Ever hear of the Princess and the Pea?
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 14, 2013, 03:14:44 pm
Pretend how? The data was there, a slider with a name showed it once set as desired.

Recovery means something was lost and got back. What is really happening is the data is there in linear. Either the gamma conversion or over-stretching has made it clip. Why not just give people gamma and stretch controls?
Title: Re: RAW Conversion Snake Oil
Post by: digitaldog on January 14, 2013, 03:18:47 pm
Recovery means something was lost and got back.

That's one interpretation. But even if the only one, with the current rendering settings, that data was lost. Using a slider called recovery brought back into view, the data that is there IF one properly sets the slider(s).
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 14, 2013, 03:35:11 pm
This other software uses the term "histogram contrast stretch". I can apply linear, logarithmic, exponential, hyperbolic, Rayleigh, curves, etc. If you don't want to clip the data, don't apply a function that does so. It seems simple.

Title: Re: RAW Conversion Snake Oil
Post by: Vladimirovich on January 14, 2013, 03:43:47 pm
Recovery means something was lost and got back. What is really happening is the data is there in linear. Either the gamma conversion or over-stretching has made it clip. Why not just give people gamma and stretch controls?

no it does not... in a typical raw converter "speak" recovery is not about "data is there" ( in a region with clipped raw channel(s) ), recovery is about postprocessing to paint (note that it is not a part of the raw conversion exactly) that part (where you have clipping) of an image using the data from unclipped raw channels and/or the data from surrounding areas in that image to make that area (where you have clipping) suitable/acceptable to your intended visual objective
Title: Re: RAW Conversion Snake Oil
Post by: digitaldog on January 14, 2013, 03:45:47 pm
no it does not... in a typical raw converter "speak" recovery is not about "data is there"

Typical raw converter speak? Where's the dictionary so I can study up?
Title: Re: RAW Conversion Snake Oil
Post by: Vladimirovich on January 14, 2013, 04:00:34 pm
Typical raw converter speak?

Adobe's ACR/LR are typical, they paint areas with clipped raw data to make it visually appealing... that is postprocessing, not raw conversion.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 14, 2013, 04:27:25 pm
no it does not... in a typical raw converter "speak" recovery is not about "data is there" ( in a region with clipped raw channel(s) ), recovery is about postprocessing to paint (note that it is not a part of the raw conversion exactly) that part (where you have clipping) of an image using the data from unclipped raw channels and/or the data from surrounding areas in that image to make that area (where you have clipping) suitable/acceptable to your intended visual objective

So it's a content fill with created data. Ok.

What about terms like "magic wand"? Isn't it all just "We have secret sauce 1 thru 10! Buy us!"

I prefer terms like USM, wavelets smooth/sharpen, Van Cittert, Richardson-Lucy, Gaussian, Poisson, statistical difference, quantile, adaptive median. You know, terms that you can learn exactly what is going on in your picture processing.
Title: Re: RAW Conversion Snake Oil
Post by: Vladimirovich on January 14, 2013, 04:37:08 pm
I prefer terms like USM, wavelets smooth/sharpen, Van Cittert, Richardson-Lucy, Gaussian, Poisson, statistical difference, quantile, adaptive median. You know, terms that you can learn exactly what is going on in your picture processing.
everybody understands that software intended to be used by many and be a market leader, can't overload its UI w/ such things... if you want that, by all means go after astro software or the likes of rawtherapee... LR/ACR have quite consistent approach and that approach is not editing by numbers (like you can in the likes of RPP for example) and not overloading the endusers w/ rawtherapee like amount of sliders.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 14, 2013, 04:55:29 pm
everybody understands that software intended to be used by many and be a market leader, can't overload its UI w/ such things... if you want that, by all means go after astro software or the likes of rawtherapee... LR/ACR have quite consistent approach and that approach is not editing by numbers (like you can in the likes of RPP for example) and not overloading the endusers w/ rawtherapee like amount of sliders.

I have chosen that route. The interface is pretty simple as can be seen in the attachment.

I did not have to content fill that sky BTW.

Anyway this is all off topic. Do you have any thoughts on color splotches from high ISO conversion?
Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 16, 2013, 06:41:37 am
Anyway this is all off topic.

What's the topic?  Snake Oil?

What is the snake oil again?  The recovery slider that no longer exists in Lightroom and ACR?
Title: Re: RAW Conversion Snake Oil
Post by: stamper on January 16, 2013, 07:13:17 am
Quote Jeremy.


What's the topic?  Snake Oil?

What is the snake oil again?  The recovery slider that no longer exists in Lightroom and ACR?

Unquote Jeremy.

Jeremy the recovery slider STILL exists in Lightroom. Change to process 2010 and you can play about with it all day long. ;D
Title: Re: RAW Conversion Snake Oil
Post by: bjanes on January 16, 2013, 04:15:07 pm
Yesterday I stumbled upon a new raw converter. The default conversion looked pretty good.

Like others, I can't discern the point of the OP's post. It appears to be more inflammatory than illuminating. I would not recommend ImagesPlus for general photographic use, but it is very useful for scientific work and sensor analysis using raw files. See my post (http://www.luminous-landscape.com/forum/index.php?topic=72957.msg591273#msg591273) in another thread for more details

Regards,

Bill
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 16, 2013, 06:53:19 pm
There is nothing wrong with a bit of controversy. This is not a place to submit dissertations, its a web forum.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 16, 2013, 07:16:24 pm
Like others, I can't discern the point of the OP's post. It appears to be more inflammatory than illuminating. I would not recommend ImagesPlus for general photographic use, but it is very useful for scientific work and sensor analysis using raw files. See my post (http://www.luminous-landscape.com/forum/index.php?topic=72957.msg591273#msg591273) in another thread for more details

Regards,

Bill

The topic was leaving in high iso chroma noise if you can't properly remove it. Eric showed a side by side of the improvement in LR2 vs 3 for this. There was still color banding created by the software in the file.

Since you have access to IPlus and the latest versions of probably every top Raw converter you can show the side by side of Iplus and LR4 on an ISO 3200 or 6400 shot. With NR and without.

I cannot. I did provide shots from Sony raw converter, Picture Ninja and a straight conversion from IPlus. All the raw converters were leaving color splotches from smoothing in the file. They were artificial drops of color from being unable to smooth the noise properly. If you do smooth the noise you wipe out all detail in the shot. You have no edges, even from a very sharp lens.

Its very simple to end the controversy which is "are raw converters good enough on high ISO?" A high ISO file with noise removed and NO sharpening can be attached cropped. If the file is as sharp as the same file from Iplus without NR then the raw converter has not damaged your picture, it has only removed noise. If you have to use extensive sharpening routines to reverse what the software did in NR there is room for improvement.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 16, 2013, 10:19:44 pm
Here is a way for independent verification. Anyone can download the RAW of the best DSLR around the D800 from Imaging Resource. They are good enough to provide RAWs for your review.

Here is the raw of their ISO3200 shot NR set to 0 in camera.
http://www.imaging-resource.com/PRODS/nikon-d800/D800hSLI03200NR0.NEF.HTM (http://www.imaging-resource.com/PRODS/nikon-d800/D800hSLI03200NR0.NEF.HTM)

Here is my jpg of the conversion. I am going out on a limb to say the jpg of a conversion to 32bit fit is probably sharper than what your RAW converter provides. Nothing has been done to the file besides RAW to FIT and save as JPG. I tried to provide a rar'd tiff but it was too big for the upload site. Bob and anyone else can do a difference if they follow the same steps. No NR, no sharpening or anything else is applied, it is as your sensor sees it after de-bayering. You will have to do your own gamma.
http://www.sendspace.com/file/nrkgdg (http://www.sendspace.com/file/nrkgdg)

Test your converter against the detail. Default settings, with NR, with NR and sharpening. I bet you will have to "capture sharpen", not because the file was not sharp, but because your software blurred it.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 16, 2013, 11:12:15 pm
Here is the same file with white bal and brightening. I fealt absolutely no need to do NR or sharpening. I left it alone. Even the chroma noise looks fine if its individual pixels rather than clumps created by your converter.

http://www.sendspace.com/file/w1tq12 (http://www.sendspace.com/file/w1tq12)

This is a very nice image. For ISO 3200 its incredible.
Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 16, 2013, 11:37:04 pm
Tilting at windmills ...

(http://upload.wikimedia.org/wikipedia/commons/7/75/Don_Quixote_6.jpg)
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 17, 2013, 01:04:18 am
Tilting at windmills ...

(http://upload.wikimedia.org/wikipedia/commons/7/75/Don_Quixote_6.jpg)

http://en.wiktionary.org/wiki/all_hat_and_no_cattle (http://en.wiktionary.org/wiki/all_hat_and_no_cattle)
Title: Re: RAW Conversion Snake Oil
Post by: 32BT on January 17, 2013, 03:12:24 am
[X] clueless

besides, these type of posts without real names, doesn't that equate to trolling…

Title: Re: RAW Conversion Snake Oil
Post by: 32BT on January 17, 2013, 03:29:52 am
The whole point of RAW conversion is nicely summed up by this example. Notice the checkerboard patterns? Those are in a favourable area of the image, that is: an area which one would render to neutral gray. In neutral gray, demosaicing shouldn't be necessary.

Now the question is: how do you propose to remove to checkerboard patterns while maintaining your preferred noise pattern?

How do you sharpen this image for output?

Or do you also like the checkerboard pattern?
Title: Re: RAW Conversion Snake Oil
Post by: Bart_van_der_Wolf on January 17, 2013, 07:45:57 am
The whole point of RAW conversion is nicely summed up by this example. Notice the checkerboard patterns? Those are in a favourable area of the image, that is: an area which one would render to neutral gray. In neutral gray, demosaicing shouldn't be necessary.

Hi Oscar,

To achieve a neutral grey, demosaicing is also necessary, because otherwise it would not be possible to know that it's neutral grey, or a subtle/pastel color, or detail afterall.

Quote
Now the question is: how do you propose to remove to checkerboard patterns while maintaining your preferred noise pattern?


By using a different Rawconverter? These mazing and zipper artifacts are a by-product of a demosaicing algorithm that tries to extract more detail than is available, yet is attempting to keep the speed of conversion high. I've attached an unsharpened CaptureOne Pro V7.02 conversion (one of many possible conversions), at 400 percent (Nearest Neighbor interpolated) zoom.

Cheers,
Bart
Title: Re: RAW Conversion Snake Oil
Post by: 32BT on January 17, 2013, 11:01:06 am
Hi Oscar,

To achieve a neutral grey, demosaicing is also necessary, because otherwise it would not be possible to know that it's neutral grey, or a subtle/pastel color, or detail afterall.
 
By using a different Rawconverter? These mazing and zipper artifacts are a by-product of a demosaicing algorithm that tries to extract more detail than is available, yet is attempting to keep the speed of conversion high. I've attached an unsharpened CaptureOne Pro V7.02 conversion (one of many possible conversions), at 400 percent (Nearest Neighbor interpolated) zoom.

Cheers,
Bart

LOL, you preaching to the choir now?

OP was proposing that awful looking colornoise is the result of demosaicing, and while he is right, it is actually exactly that subtle compromise between detail and noise that needs to be solved by the demosaic algorithm. Simply focussing on the colornoise and then pointing out "failures" on the side of the converter is not exactly useful. So, to counter the proposition of the conversion he offered, i simply point out where the opposite fails.


In order to make this discussion at least somewhat useful to the readers, I will answer your suggestions with some ridiculous counter-suggestions, just to get the obvious stated:

To achieve a neutral grey, demosaicing is also necessary, because otherwise it would not be possible to know that it's neutral grey, or a subtle/pastel color, or detail afterall.

To achieve neutral gray one simply has to equalize the RGB values for each pixel. Certainly that does not require demosaicing.


By using a different Rawconverter? These mazing and zipper artifacts are a by-product of a demosaicing algorithm that tries to extract more detail than is available, yet is attempting to keep the speed of conversion high.

Seems more like a byproduct of not doing any conversion. Which would indeed provide more natural noise characteristics, but doesn't particularly help the look of normal detail in a file.

For reference a conversion with a different converter attached, without any filtering whatsoever. Notice that the text and logo are quite eligible and sharp, but the colornoise in the bottle does look somewhat spiky. Not anything that a reasonable RAW converter can not tackle, even while maintaining sharpness overall, but it does look unnatural.



Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 17, 2013, 12:13:19 pm
Thanks for pointing out the checker-boarding at 300%, I never noticed it.

Your attachment at 200% has significantly more noise than the jpg I provided. See side by side attached.

I was able to get the best detail from Raw Therapee with it's amaze de-bayer. It looked a hair crisper than the output from IPlus. Lines in the color wheel we a hair thinner. The noise when everything was turned off was basically the same as IPlus. The default looked quite a bit worse with lots of black peppering on the dark areas. With NR and sharpening it could look like Iplus without the noise. Its a fairly impressive program. Yes, RT is color managed.

Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 17, 2013, 12:18:37 pm
Wake up and smell the irrelevance of this discussion.

You remind me of the guy in High School who couldn't stop talking about the "rotary" engine in his Mazda RX7. 

Why do you keep jumping into this thread that you have no interest in just to denigrate it?
Provide a comparison, show I am mistaken, do something useful or stay out.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 17, 2013, 12:51:47 pm
Here is RT with everything turned off. It seems a bit crisper, a bit more artificial. Of the 2 for non-pixel peeping, I prefer Images Plus.

So the point of the thread, ISO 3200 noise, what everyone tries to avoid like plague, is not the shot noise everyone thinks it is. It is RAW converter noise.
Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 17, 2013, 01:39:27 pm
Why do you keep jumping into this thread that you have no interest in just to denigrate it?
Provide a comparison, show I am mistaken, do something useful or stay out.

Because you make silly and provocative remarks that caught my attention.

Poke and get poked ... law of the jungle ...
Title: Re: RAW Conversion Snake Oil
Post by: 32BT on January 17, 2013, 01:51:54 pm
Here is RT with everything turned off. It seems a bit crisper, a bit more artificial. Of the 2 for non-pixel peeping, I prefer Images Plus.

So the point of the thread, ISO 3200 noise, what everyone tries to avoid like plague, is not the shot noise everyone thinks it is. It is RAW converter noise.

No, the color noise as depicted in my previous picture is the color noise that is actually captured in the file. The fact that your raw converters do not show the noise merely means they might be applying some base-line noise mitigation. The noise is real, you should generally want to avoid it as much as possible. The luminance noise that is also part of the problem is much finer grained, and generally not as objectionable as the color splotches. So, a conversion might look like attached image, were colornoise is removed, but luminance noise isn't.

But this really is very basic knowledge, and you should possibly try to read up on the information available all over the internuts before trying to make provocative and false statements in a forum like this in order to learn about the issues involved.





 
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 17, 2013, 02:09:49 pm
No, the color noise as depicted in my previous picture is the color noise that is actually captured in the file. The fact that your raw converters do not show the noise merely means they might be applying some base-line noise mitigation. The noise is real, you should generally want to avoid it as much as possible. The luminance noise that is also part of the problem is much finer grained, and generally not as objectionable as the color splotches. So, a conversion might look like attached image, were colornoise is removed, but luminance noise isn't.

But this really is very basic knowledge, and you should possibly try to read up on the information available all over the internuts before trying to make provocative and false statements in a forum like this in order to learn about the issues involved.

 

It's amazing to me you would claim a scientific program is doing "baseline noise reduction". The color noise you presented is not captured in the file. It is an artificial pattern. It is not random at all. By providing a cleaned copy with NR and sharpening all you show is difference from the JPG I provided.

The very strong red and green color noise you showed is only there to make the NR algorithm look good. That noise is not in the picture. Real noise would be random or lines or an amp glow spot from heat in the camera.

That pattern is very artificial. I can create something similar by applying smoothing to channels. Even then I don't think I can make it look that strong from that file.

I learned from a very young age that the truth always wins in the end. There are people on this board with access to other scientific imaging programs that can verify your claims and mine.

One thing is for sure, any wedding photographers who see the ability to shoot at high ISO with minimal noise and strong detail on whites and clean blacks are going to go for that software. If a software puts noise in at baseline just to take it out with other sliders its a game.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 17, 2013, 07:31:03 pm
I added noise reduction to my own file. I don't believe any of the commercial raw converters make a file look this natural, this sharp and this noise free from that ISO3200 file.

http://www.sendspace.com/file/csicku (http://www.sendspace.com/file/csicku)
That is the end of it as far as I am concerned. I have never seen ISO3200 look like ISO200 before.

I normally shoot at 100 or 200, 400 in a pinch, 800 If I have to. Now that I understand how to get the noise out I feel free to go Up to 3200 as needed.

Added an oversharpened screenshot. This was taken to the point artifacts are building up.
Title: Re: RAW Conversion Snake Oil
Post by: 32BT on January 18, 2013, 05:36:13 am
Here are 2 interesting examples.

Example 1 compares:
1. RAW data samples in perceptual grayscale as provided by file
2. Nearest Neighbor duplication of the samples in color

Example 2 compares:
2. Nearest Neighbor duplication of the samples in color
3. Demosaic samples without any filtering

All files are processed using the same tone response which has auto-adjusted the source samples for exposure and brightness, that is: samples are distributed over the entire scale and the average perceptual brightness is at 50%. This may brighten the darktones more than you are used to seeing in your other RAW converters, which then makes colornoise more visible than what you are used to. Either way, the samples are what they are, if you look closely at the RT samples you posted, they also show the exact same colornoise, just buried in darkness, but it is there.

RAW data was read from file using DCRaw. The engines used to do conversion are proprietary, they do not use DCRaw. Since DCRaw is one of the most dense and most badly written code ever, in the entire history of software, I will not vouch for its accuracy, but since most of the academic world and scientific programs out there use it to read RAW files, I do not believe the data would be much different from those software options. (Note that I highly regard Dave's initiative as a monumental achievement for all kinds of reasons, but the coding style is simply not one of those reasons.)

Make of it what you will. If you're happy with your own way of processing, by all means use it. Other people use other methods, and use other RAW converters, not only for the processing, but for the entire production chain those converters may offer.
Title: Re: RAW Conversion Snake Oil
Post by: Bart_van_der_Wolf on January 18, 2013, 11:07:08 am
To achieve neutral gray one simply has to equalize the RGB values for each pixel. Certainly that does not require demosaicing.

Hi Oscar,

And therein lies part of the misunderstanding. In an ideal noisefree CGI image, it is possible to locally neutralize to gray, but that is utterly impossible in real life. Photon shot noise, with some added read noise, is going to add color to sensels, even if the subject being photographed is perfectly gray. The noise added to a Red filtered sensel is independent from the noise added to the neighboring Green or Blue sensel, therefore the 'color' (signal level) will be different even from the other nearby Red filtered sensels.

Since neither the sensor array nor the demosaicing software recognize 'neutral', the demosaiced (and even the non-demosaiced) color balancing will result in colored noise around the average gray level. What's more, because Red and Blue are sampled at a lower density than Green, the interpolation result for Red and Blue will have a lower spatial frequency than the original photon noise (and a lower amplitude). How much lower depends on how the full color reconstruction is tuned between Luminance and Chrominance.

It is that inevitable lower spatial frequency (coming from interpolation) that is mistaken by the OP for smearing of color as if there is a targeted attempt to suppress noise. Of course, the separate operation of noise reduction does attempt to reduce the noise at specific spatial frequencies, but it usually also masks edges and other high spatial frequency areas from such noise reduction.

Cheers,
Bart
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 18, 2013, 11:57:54 am
That sounds like a reasonable explanation Bart.

Keep in mind what put me on this was not the converter Oscar is using (whatever that is) it was see attached. When I moved the noise sliders all the way left sections of red/green color noise showed up that was >than 10 pixels across. That was in all dark areas of the file. See attached. Now, you could argue  that all the way left on the sliders is not 0 NR but noise enhancement for artistic use. I don't think anyone would buy that.

If the color noise is close to being at the pixel level, I would call it random to the best ability of the raw converter. When the red green starts to get bigger, especially taking on a directional component (repeating up/down, left/right), I would say it is not noise, it is an artificial construct of the raw converter. If you look at the sample provided further up the thread with strong color noise in shadows zoomed in it takes on that pattern.

Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 18, 2013, 12:09:17 pm
This is a zoom of the noise form the other poster above. There is a very clear up/down, left/right component to it.
Title: Re: RAW Conversion Snake Oil
Post by: 32BT on January 18, 2013, 01:13:12 pm
This is a zoom of the noise form the other poster above. There is a very clear up/down, left/right component to it.

Good, you are starting to see the light.

That component is exactly the trade-off that each RAW converter needs to make somewhere and at some threshold. That threshold is different for each camera and each iso. It needs to be calibrated. It defines the final look of the file. You can have more blocky noise, or you can have more edgy noise. It would be useful if you could have an interactive slider for it, but alas, it is too deep within the engine to be viable at this stage of computing, and most people wouldn't know what to look for to set it. Not to mention that setting it for one part of the image can completely screw up another part.

Attached you can see what happens if you move the threshold too high. You can have your preferred noise pattern, but the result is checkerboards, or you have to accept some interaction within the noise, but at least get acceptable detail. 

Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 18, 2013, 01:16:54 pm
Good, you are starting to see the light.

Can we agree that this noise is not artificially inserted by the developers of the conversion software in an attempt to mislead users?
Title: Re: RAW Conversion Snake Oil
Post by: 32BT on January 18, 2013, 02:07:43 pm
Can we agree that this noise is not artificially inserted by the developers of the conversion software in an attempt to mislead users?

I should hope I never implied that either directly or indirectly…

The noise is in the capture. Due to the disconnect between adjacent pixels as well as the individual channels, there is no way of knowing what constitutes noise, and what should contribute to interpolated signal. One can set a threshold, and then use different interpolation (or even generating a random value) depending on the signal to noise ratio, but a value has to be selected for the missing channels.

The latter can create more edgy noise (gradient based interpolation), or more blocky noise (linear interpolation), or even more noisy noise (inserting random values), but something has to be chosen below threshold. Incidentally that also coincides with the discussions we had previously about Bart's star image and the AA filter. Beyond nyquist, one can choose several methods of rendition, more blurring or more false detail. In the end it will all contribute to the final look of the image.

Probably even on a subconscious level. If the interpolation routines repeatedly select the opposite direction that the eye-brain combination chooses, then I am convinced that leads to very uncomfortable viewing experience…


Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 18, 2013, 02:42:53 pm
People still have to compare their version to the clean natural look of the full size jpg I provided. I doubt anyone can get close. NSA could beat my version, not many others.
Any if anyone doubts that file is from the sameISO3200 version. I am doing a conversion of an ISO6400 Sony A77 provided by someone else. With 24MP on APS-C behind a 1/2 stop pellicle the A77 is a good challenge.
Title: Re: RAW Conversion Snake Oil
Post by: 32BT on January 18, 2013, 02:52:46 pm
I doubt anyone can get close.

Indeed. Especially by your standards. In fact, why don't you give Fuji a call. I have it from reliable sources that people are seeking a solution to the rather dreadful conversions that the mainstream tools currently offer. I'm sure your methodology will instantly solve 20+ years of failed debayering experience that camera and digital imaging companies apparently exhibit.
Title: Re: RAW Conversion Snake Oil
Post by: jeremypayne on January 18, 2013, 02:53:26 pm
I should hope I never implied that either directly or indirectly…

No, you did not ... but Mr Fine Art said so quite explicitly:

"The very strong red and green color noise you showed is only there to make the NR algorithm look good. That noise is not in the picture ...  If a software puts noise in at baseline just to take it out with other sliders its a game."
Title: Re: RAW Conversion Snake Oil
Post by: 32BT on January 18, 2013, 02:59:25 pm
No, you did not ... but Mr Fine Art said so quite explicitly:

"The very strong red and green color noise you showed is only there to make the NR algorithm look good. That noise is not in the picture ...  If a software puts noise in at baseline just to take it out with other sliders its a game."


Ah, yes, I chose to ignore that for the sake of my own sanity...
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 18, 2013, 04:30:08 pm
Sony A77 ISO 6400 provided by a guy in England. Only the one file was provided.

Rendered with everything off in IDC Note the color noise stays a fine random pattern.
(http://farm9.staticflickr.com/8235/8392362787_b4d569a695_o.jpg)

Converted in Images Plus no adjustments. Both versions are weighted to dark colors.
(http://farm9.staticflickr.com/8374/8392362827_e80fed8065_o.jpg)

Images Plus with curves, NR, Sharpening
(http://farm9.staticflickr.com/8221/8392362847_049c8f4967_o.jpg)

IDC all off 100% crop Note the noise stays a fine spot pattern with no clumps.
(http://farm9.staticflickr.com/8336/8392380995_fe5bac5187_o.jpg)

Images Plus with curves, NR, Sharpening 100% crop. Notice the clumping of noise. It is created by me with the smoothing routines. The same larger spots of red and green that you see in raw converters. It is not noise from the sensor, it is smoothing routines.
(http://farm9.staticflickr.com/8229/8392380957_f0d8b88296_o.jpg)

Edit: All these images are 1920x1080 if you open the image.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 18, 2013, 10:12:31 pm
A different kind of smoothing that makes color clumps! I can make the clumps all kinds of shapes via different smoothing.
(http://farm9.staticflickr.com/8356/8393128211_bdb81f6ab8_o.jpg)

So the key to really good noise reduction is here. I'm not going to type it out again.
http://www.dyxum.com/DFORUM/looking-for-high-iso-a77-raw_topic95123_post1129602.html#top (http://www.dyxum.com/DFORUM/looking-for-high-iso-a77-raw_topic95123_post1129602.html#top)

You have to do it yourself in individual channels.
Title: Re: RAW Conversion Snake Oil
Post by: Bart_van_der_Wolf on January 19, 2013, 10:57:56 am
So the key to really good noise reduction is here.

Hi,

Do you realise what it actually is that is happening? If I understand your procedure, you seem to be using the low resolution color separations from the R, G, and B, filtered sensels from the Bayer CFA data. These separations are sampled at every 2nd sensel, therefore at 50% of the Nyquist frequency. You then reduce noise at those spatial frequencies, and then do the Demosaicing on that frequency attenuated/filtered data.

Doing so with Images Plus, will unfortunately mean that Color management is out of the window, but one does have the benefit of doing the noiseband filtering at a high numerical precision, and subsequently converting the gamma to something like 1/2.2 will be able to use that precision for a slightly more accurate result before rounding to 16-bit channels.

It also means that you sacrifice accuracy in luminance demosaicing (we've seen the zipper artifacts), which would not happen with a proper dedicated noise removal tool which masks the detail, and only removes a tweakable amount of noise from low spatial frequency areas. I suppose a profiled (I don't have a profile for the cameras you showed samples of, so I can't show the optimal result) NeatImage run would achieve something similar. Also TopazLabs Denoise plugin delivers very useful results.

Cheers,
Bart
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 19, 2013, 11:54:03 am
Bart,

Yes, its very valuable to use the independent NR programs. I did my first test using the older noise ninja 2 with pretty amazing results. I expect to pick a newer NR package. Images plus also has extensive NR capability. It has several routines that preserve detail at the pixel level. You will not see your details smeared out. Look at the screenshot above I called "oversharpened". I was running the adaptive richardson-lucy on the luminance channel. The artifacts from too many cycles are easy to spot clean.

Its at a point where any theorizing about lost color channel detail is to ignore experimental results. It becomes mental exercise for it's own sake. This was my first pass at ISO3200.
http://fs05n5.sendspace.com/dl/b6ee75e0ce6682a4ecb9a9d059e5e1ce/50facb6d1781b996/w1tq12/CVT_D800hSLI03200NR0%20curves.jpg (http://fs05n5.sendspace.com/dl/b6ee75e0ce6682a4ecb9a9d059e5e1ce/50facb6d1781b996/w1tq12/CVT_D800hSLI03200NR0%20curves.jpg)
My technique now is much better. The method is posted in that thread.
Title: Re: RAW Conversion Snake Oil
Post by: Fine_Art on January 19, 2013, 12:35:07 pm
Actually, I take that back. Theorizing about it is valuable. What just occurred to me is your (Bart) explanation of bayer filling in the "Foveon and full sensor capture" thread is very relevant here. In that thread you convinced me that de-bayer can do as good a job as full sensor capture on some scenes. Ok, look at the noise per channel using this method. A lot of what you are using NR to fix in this method is the black holes and bright jumps that are similar to the missing pixels in bayer.

Closing this down to discuss NR under a less controversial headline.
Arthur