software uprez vs. print at 200%

[Jim Kasson]

Photographs: http://www.kasson.com/

Jim, really nice UW shots! I hadn't known you did that :~)

Thanks, Jeff. The person who took the underwater stuff was a much younger man. He even used film for all but one series...

Jim

[steveblennis]

Here you go...

wow all of info thanks.  i see some are 'finest detail' related. I was wondering about that checkbox.

[steveblennis]

Actually, resampling to the printer's reported resolution CAN help canvas if you have image detail that has strong high contras diagonals (or circles or other texture that has a specific pattern) because even with canvas and matte watercolor paper, you can still see the printer resampling aliasing errors in cases like this.

Thanks nice tip.

[Bart_van_der_Wolf]

Actually, resampling to the printer's reported resolution CAN help canvas if you have image detail that has strong high contras diagonals (or circles or other texture that has a specific pattern) because even with canvas and matte watercolor paper, you can still see the printer resampling aliasing errors in cases like this.

I agree with Jeff. I've produced canvas prints at 720 (!) PPI (which allowed to also output sharpen to a higher degree!) that looked very sharp. A lot also depends on the particular type of canvas, and for the surface areas that have the same distance to the jet nozzles as with glossy paper, the sharpness can be identical.

I see no reason to lower the quality if it takes no more effort than resampling to a fixed PPI. I still need to output sharpen after that, and I won't need to depend on whatever flavor of resampling the printer driver utilizes, which might even differ between OS versions (OS X versus Windows) according to some.

Cheers,
Bart

[steveblennis]

First test done. I'd say pretty good success, looks good considering it wasnt a huge file in the first place.

I did click the 'finest detail' with a little bit of a test in mind. After the fact I see it seems to resample to 720,
and only be good for more vector type images. but it still came out good.

Im going to do another copy without the 'finest detail'.


Im on to a 30x30 next.


Thanks for all the info, with time, canvas and ink = money. Im glad to have prepared first.

What do the woodworkers say, "measure twice, cut once".

[Schewe]

I did click the 'finest detail' with a little bit of a test in mind. After the fact I see it seems to resample to 720,
and only be good for more vector type images. but it still came out good.

To be clear, Epson has pretty much said Finest Detail was only good for vector art, but, they've been too conservative in stating it's usefulness. We've proven that Finest Detail CAN help photographic images where there is high contrast diagonal (and circles) and other high frequency image detail. In these cases, the images get the same benefit of improving aliased edges as the vector artwork does. In essence, it's solving the problem of refining the aliased edges of both photos and vector art. So, what's good for the goose is good for the gander, so to speak.

I've talked at length with the EPson people and they are aware of this new found use for printing photos. It's just they've never gotten around to doing the testing and work they would need to do to make these claims of improvement.

In point of fact, there's actually a technique to have the printer report it's native resolution to be 1440 which is 2x the Finest Detail. The only trick (and limitation) is it'll ONLY work if you select Finest Detail and ALSO select certain media types-specifically, certain proofing papers. The reason for this is in proofing for halftone screening, printing out at 1440 can better help resolve an actual halftone dot.

I tested this using proofing papers to compare 720PPI with Finest Detail and 1440 with Finest Detail and with the same photos I could see no visible difference–nowhere near what I could see printing at 360 without Finest Detail and with 720 with Finest Detail.

In order to use this 1440 trick, you would have to make custom profiles using the Proofing media settings and using your own paper (non-proofing paper) to get optimal results for tone & color.

Since I couldn't see any difference (and I know what to look for) I decided that was a rabbit hole I didn't need to go down. So, the bottom line is if the native rez is less than 360, I upsample to 360 (and then sharpen) if the native rez is above 360 but below 720, I upsample and sharpen. If the native rez is about 720, I downsample to 720 and sharpen. The reasoning for downsampling is again to take the resampling away from the print pipeline.

[steveblennis]

Thanks great info. it really puts it all in perspective.

Ive been selling prints now for about 2 years, I started off pretty green, but with decent results.
In the last year getting into groove, and now really trying to dig into some of these nuance things to bring my prints to as much of a pro level as I can.


Thanks great stuff.

[steveblennis]

High Speed setting question.

I pretty much always have this checked. As a Side note: I did see that if you have 'Finest Detail' checked, you should probably uncheck 'High Speed'.

But the question is.......


Does unchecking 'High Speed' give you any better quality difference. or is 'High Speed' the way to go generally?


I would take quality over speed.

[Jim Kasson]

Does unchecking 'High Speed' give you any better quality difference. or is 'High Speed' the way to go generally?

If memory serves, checking High-Speed enables bidirectional printing. There is a possibility of increased dynamic registration errors when the print head has to hit the same spot moving from either side. I always leave it unchecked, because I'm not in a hurry. But I've never done any comparative testing. I would think the results would depend on your particular (serial #, not model #) printer.

Jim

[Schewe]

Does unchecking 'High Speed' give you any better quality difference. or is 'High Speed' the way to go generally?

Depends, when was the last time you did a head alignment? If you have the head well aligned (I use auto-align) then high speed on/off is gonna be real close. However, if you are working with high rez images and printing out 720ppi images with the printer set to Finest Detail and 2880 print resolution, you might ("might") see some slight benefit due to the more accurate per swath registration...I do head alignments whenever I change papers and generally print with high-speed on. But, when I'm printing out at 720ppi with Finest Detail, I turn it off. Note, when printing at 720ppi, I'm generally making smaller prints (less than 16x20) that will be viewed much closer than larger prints. For that reason I think it's marginally optimal to print with high-speed off.

[darlingm]

High Speed setting question.

I pretty much always have this checked. As a Side note: I did see that if you have 'Finest Detail' checked, you should probably uncheck 'High Speed'.

But the question is.......


Does unchecking 'High Speed' give you any better quality difference. or is 'High Speed' the way to go generally?


I would take quality over speed.

High speed (bidirectional) printing can also cause banding in large black/near black areas on certain media types.  Some can handle it, some can't.

[steveblennis]

High speed (bidirectional) printing can also cause banding in large black/near black areas on certain media types.  Some can handle it, some can't.

ah, yeah i did an almost all black canvas print. that is tough enough with white spotting etc.

im on canvas, but i bet thats a real pain on a nice glossy print.

[steveblennis]

wow ok, knocked out my 2nd print, up to 30x30ish.

came out great

starting:
2000 x 1994 180ppi  1.43MB

to:
11999 x 12031 360ppi   2.39GB


super happy

[JRSmit]

Jim would liketo see the results i  a sort of split view, as the PR maybe specatacular on the graphical part but is not without artefacts on the tree branches and the circular grey gradient is not as smooth as f.i.the LR result.

[steveblennis]

My 2nd print. Its a Frantisek Kupka watercolor, 1920-ish, so pretty smooth flat, like vector graphic.
Probably lends itself to uprezzing, but looks great. 31x31 printed area.




Update on 'Finest Details' - Made 2 prints, canvas, 360 ppi etc etc

On a very painterly artist print, 'Finest Details' wins out. Ever so subtle at 6-12 inches. About a 10%-ish pop in sharpness (contrast) -as best as I can describe.

Oddly enough it noticeable in the finest details.  The very small canvas pattern in areas  is mostly noticeable.

[JRSmit]

Steve, same effect with my prints. This "pop" is quite visible. On my epson 4900 my standard setup is 720 ppi and finedetails on, and highspeed on. Even for fine art papers, as the effect is at least less bleed of ink at high contrast edges on the paper. (720 ppi does put ( a little) more ink on the paper) Also as Jeff's article points out, a smoother result on tonal and saturation changes.

[Bart_van_der_Wolf]

On a very painterly artist print, 'Finest Details' wins out. Ever so subtle at 6-12 inches. About a 10%-ish pop in sharpness (contrast) -as best as I can describe.

Hi Steve,

There is more ... Once we have upsampled to the 600/720 PPI native printer driver resolution, we can add not only output sharpening to counteract ink diffusion, but we can also do more accurate detail enhancement, e.g. with a plugin such as Topaz Labs Detail. It allows to not just sharpen the micro-detail, but it also allows to give larger structural detail in the image more (or less) definition (typically used a bit earlier in the creative sharpening part of processing). There will be no halos added, just detail enhancement which will also allow the image to 'pop' at more than a nose length away. And of course one can also add noise which becomes almost subliminal at this detail level.

Oddly enough it noticeable in the finest details.  The very small canvas pattern in areas  is mostly noticeable.

Yes, that's what I see on canvas prints as well. Details remain very sharp, especially at the highest native printer driver resolution, and obviously the canvas structure dominates in regions that otherwise have little subject feature content.

Cheers,
Bart

[Bart_van_der_Wolf]

Even for fine art papers, as the effect is at least less bleed of ink at high contrast edges on the paper. (720 ppi does put ( a little) more ink on the paper)

Hi Jan,

The dithering pattern at 720 PPI is supposed to be made up of smaller droplets, which allows to have sharper edge detail that otherwise would be rendered less accurately with larger droplets. In other regions of the image that may take more droplets to build up density and cover the paper substrate when the ink doesn't diffuse much. I assume that the dithering algorithms could also be changed to use larger droplets in those not detail regions, so things may change (although selling more ink (~liquid gold) is a goal for the manufacturers).

Cheers,
Bart

[Jim Kasson]

Jim would liketo see the results i  a sort of split view, as the PR maybe specatacular on the graphical part but is not without artefacts on the tree branches and the circular grey gradient is not as smooth as f.i.the LR result.

I understand. The split-screen approach has a problem in that you're not looking at the same part of each image, unless you have a slider like they do with the before and after tsunami pictures, and I don't know how to do that. What I've done with some other images that were hard to compare on the screen was supply Photoshop composite images with each sub image in a layer. I like what Lloyd Chambers does for his comparisons, but I don't know how to do that either.

To your second point. Yes, unfortunately, there's no one algorithm that delivers stunning performance for every kind of image.

That said, I'm not anxious to repeat the resampling algorithm testing. One, The proprietary algorithms can change over time, so there's a finite shelf like to testing them. Two, since Lightroom 4, I've been happy enough with the job that Lr does that I only use less-convenient techniques when I get a print order or I have an exhibition. Neither one of those things is a weekly occurrence -- I wish it were -- so I mostly just use Lr. My motivations for my blog are so that others can profit from what I'm doing for myself, so if I'm no longer spending time testing resampling algorithms for my own work, I'm no longer doing it at all. Sorry.

The good news is that, if you have a scanner, you can do everything but the photomicrographs yourself. Or, skip the scanner and get up close and personal with the print. You now know that the resampling algorithm can make a difference, and that, among good algorithms, the difference is usually subtle.

I'll be doing another post on the Lr3-->Lr4 print sharpening change. Foreshadowing: it wasn't a change to the sharpening algorithm per se.

Jim

[Jim Kasson]

I'll be doing another post on the Lr3-->Lr4 print sharpening change. Foreshadowing: it wasn't a change to the sharpening algorithm per se.

I was on a panel on raw processing about a year ago, and so was Eric Chan. At the break, I congratulated him on the big improvements in resizing in Lightroom 4. He said that the algorithms were similar; the big change was that, rather than doing the calcs in the standard Lr working space, which has a gamma of one, they were doing the resizing in a gamma encoded space which is more perceptually uniform. We didn't discuss the gamma, but it's probably either the ProPhotoRGB gamma of 1.8, or 2.2.

That's what I was going to report to you all. But, me being me, I had to do some testing first. I wrote a little Matlab script to upres a test image by 80% at gammas from 1.0 to 3.8 using bicubic interpolation:



When I ran it, I did see some differences. But they were very subtle; nothing like the differences between Lr 3 resampling and Lr 4 resampling.

I scratched my head. Then I thought that there's usually sharpening associated with up-resing. So I modified my script to do unsharp masking at the same gamma set:



Now there was a big difference, with the images that were sharpened at higher gammas being crisper. This could be a good thing or a bad thing, depending on what effects you're trying to achieve.

Lessons:

1) although it's a weak effect, people comparing resizing algorithms should probably take pains to make sure they do all their resizings at the same gamma, and should report that gamma when they report the results.

2) people comparing sharpening algorithms should definitely take pains to make sure they do all their sharpening at the same gamma, and should report that gamma when they report the results.

I'll have images up on my blog in a few days -- I've got a backlog.

Jim