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Author Topic: C1 11: jpg processing file size bloat  (Read 2023 times)

The View

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C1 11: jpg processing file size bloat
« on: February 27, 2018, 01:51:40 pm »

I have this problem with all jpg files:

At a 1200px long edge jpg file at 73% C1 11 estimates output size 139kb, but the actual output size is 795kb - more than six times as large.

In Photoshop I can create high quality files that easily match the 139kb size.

Why can't C1 match its own output size predictions?

I cannot output preview images for clients as I cannot send them the insanely huge folders this would give.

What's wrong with jpg processing in C1?
« Last Edit: February 27, 2018, 02:33:08 pm by The View »
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Bart_van_der_Wolf

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Re: C1 11: jpg processing file size bloat
« Reply #1 on: February 28, 2018, 01:25:06 pm »

I have this problem with all jpg files:

At a 1200px long edge jpg file at 73% C1 11 estimates output size 139kb, but the actual output size is 795kb - more than six times as large.

Hi,

I don't know why there is such a discrepancy between the estimated and actual file sizes. The only way to get a somewhat reliable estimate is through iterative trial and error, which takes time. So I can only assume that C1 uses a heuristic instead of iterative trial and error. To reduce the final file size, you'd obviously have to reduce the quality setting further.

You can try to reduce the file size by starting with a 100% quality, and then reprocessing the JPEGs with a program like JPEGmini.

Quote
What's wrong with jpg processing in C1?

Not much, but the size prediction could be improved. The JPEG quality is apparently pretty good, because only quality settings of 75% or more can be usably reduced (say 25% or more), but lower settings  cannot be reduced much without visibly losing quality.

If other applications compress much more than e.g. JPEGmini or similar are willing to do, one could wonder about the resulting quality.

Cheers,
Bart

P.S. It is possible to further reduce JPEG sizes significantly but with a minor loss of quality. Google has developed a process called Guetzli. But that process is very very slow (up to 2 minutes per image in the implementation that I'm using, and it strips all metadata), so mostly usable for image resources on Websites which results in considerably faster loading pages and lower bandwidth requirements.
« Last Edit: February 28, 2018, 01:51:43 pm by BartvanderWolf »
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The View

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Re: C1 11: jpg processing file size bloat
« Reply #2 on: February 28, 2018, 06:20:13 pm »

The file size cannot be reduced to a useful amount in C1.

712 kb was the lowest size and at 55% - at this amount the image was already ruined by the compression.

In Photoshop I could easily get the 150kb approximate file size predicted - export TIFF - shrink TIFF - create JPEG. Excellent quality.

So in this case the export module doesn't work for JPEG. It has never worked for JPEG. But I'm getting fed up now because some clients want a high number of proofs and I have to show them all of the good images, which can run in the hundreds. Three 500 mb files to the client. So elegant.

Phase One needs to tackle the problem this software has. Each time you pay for an upgrade, the basic problems are still there.

I have created a support case at Phase One and see what they say.

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Jeff

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Re: C1 11: jpg processing file size bloat
« Reply #3 on: March 02, 2018, 12:50:42 pm »

Rather irritating but something one has to live with  :(

I get both situations.

Estimated size < processed actual size
Estimated size > processed actual size.

It appears to depend on whether I have cropped the original size but I have no scientific proof of that.
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JimDK

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Re: C1 11: jpg processing file size bloat
« Reply #4 on: March 02, 2018, 04:40:56 pm »

I have this problem with all jpg files:

At a 1200px long edge jpg file at 73% C1 11 estimates output size 139kb, but the actual output size is 795kb - more than six times as large.

In Photoshop I can create high quality files that easily match the 139kb size.

Why can't C1 match its own output size predictions?

I cannot output preview images for clients as I cannot send them the insanely huge folders this would give.

What's wrong with jpg processing in C1?

Try unchecking the "File icon - Create thumbnails on save" option.
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The View

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Re: C1 11: jpg processing file size bloat
« Reply #5 on: March 14, 2018, 01:40:26 pm »

I created a support case with Phase One and their only input so far is to not create thumbnails.

When you uncheck "create thumbnail" you can reduce the file size.

But it is still 250% of the original estimate, instead of 142kb it is 345 kb.

So there's work there to do for Phase One.

« Last Edit: March 14, 2018, 01:51:29 pm by The View »
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mediumcool

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Re: C1 11: jpg processing file size bloat
« Reply #6 on: March 19, 2018, 12:28:42 pm »

I always export files from C1 to Pixelmator for final JPEG output (I use 8-bit TIFF as the transfer format). Pm KILLS Photoshop for small JPEG file size, in my experience, and it does a mean 2-pixel keyline too. If you use Windows—
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