JPEG Image Discrepancies Between "Make Web Contact Sheet" and Process Tab

[Ronald Nyein Zaw Tan]

Greetings and salutations,

I have a favor to ask users of C1PRO 7.1.6 and will you mind following these simple steps and let me know if you observe image discrepancies between the JPEG exported from Process Tab and the JPEG via the File >> Make Web Contact Sheet (MWCS) feature within C1PRO7.1.6. I recently reported a finding to P1 Tech Support and I want to know if others could acknowledge my findings to procure more data.

JPEG Process Recipe (PR): JPEG, 8-Bit; ICC Profile: sRGB IEC61966-2.1; Resolution: 72 PPI; Scale: Long Edge @ 1280 Pixels; Disable Sharpening Unchecked

Web Contact Sheet Settings (WCSS): This is going to be "relative" because we can't input numbers, I am using the eleven markings to best share my settings. These "markings" are little marks on the draggable scale (evenly-spaced) and you'll know what I mean. Thumbnail Size: 3.5 marking from the left; Preview Size: 3.5 marking from the left; Quality: 11 marking from the left (max value).

Using the settings, will you let me know if you could determine image quality discrepancies? The standard or basis image is the JPEG processed from the Process Tab using the aforementioned settings. I am thinking, there is something wonky going on with the Web Contact Sheet feature.

Method

1) Open Photoshop and open the JPEG exported from PR.

2) To open the JPEG from WCSS, you'll have to go into the folder you made for the MWCS. In that folder, you'll see: index.htm and three folders: photos, scripts, and theme. Go into "photos" >> "previews." You should see the single JPEG you are using to test image discrepancy. Open that JPEG into Photoshop.

3) Try to arrange the images in PS so they are shown adjacent to each other.

Questions

1) Do you see any image discrepancies?
2) Do you see an undesired artifacting fringes in the background? In my example, I am using a Thunder Grey and I have applied my style to color grade the image.

Assumptions

1) I am on a dual-monitor setup with both color-managed workflow: The GPU is outputting the differing LUT ICCv4 profiles to each of my monitors accordingly.

2) OpenCL settings for C1PRO7.1.6 is set to both "Auto."

3) Windows 8.1 PRO (latest and stable updates) have Color Management (CM) set properly and both the operating system CM and C1PRO CM is set to "Perceptual."

Data and Results: The two images were processed and procured using the settings above. Images are are 72 PPI @ sRGB @ 100% Quality. Left JPEG was process via PR and image on the right (with problems) is via MWCS.

Link 1: http://guest.ronaldnztan.com/Screen-Shot-72PPI.jpg.

Link 2 (Settings ZEROED): http://guest.ronaldnztan.com/Screen-Shot-72PPI-ZEROED.jpg.

I am trying to make sense and understanding why I am observing the image discrepancies. I want to know if this is an isolated observation only for me or can similar discrepancies are seen by others?

[colinm]

I think the issue here is that you're expecting a single JPEG quality scale.

Make Web Contact Sheet is a tool with a single function: Making contact sheets to toss up on the web for quick viewing and approval. Its quality slider exists within the scope of that function. As you said yourself, MWCS settings are relative.  

Creating an "uncompressed" JPEG would create uselessly large files (especially working with MFDBs) so MWCS tops out at a setting that balances file size and image quality. MWCS is intended for a client to say "Love that pose and that lighting," not to judge posterization in a difficult gradation. If you need less compression, you'll have to run your images through the process workflow instead.

[Doug Peterson]

I think the issue here is that you're expecting a single JPEG quality scale.

Make Web Contact Sheet is a tool with a single function: Making contact sheets to toss up on the web for quick viewing and approval. Its quality slider exists within the scope of that function. As you said yourself, MWCS settings are relative.  

Creating an "uncompressed" JPEG would create uselessly large files (especially working with MFDBs) so MWCS tops out at a setting that balances file size and image quality. MWCS is intended for a client to say "Love that pose and that lighting," not to judge posterization in a difficult gradation. If you need less compression, you'll have to run your images through the process workflow instead.

+1

[Ronald Nyein Zaw Tan]

I'd be happy to report that P1 Tech Support reached me and made me understand why I was seeing the discrepancies. I also told them how much I rely on C1PRO in my photography work that if version 8 was announce this week, I'd say, "Shut up and take my 99 USD!!!"

C1PRO is an a great piece of software and I now accepted it is what it is and the discrepancies I had observed are within specification and expected, due to the purposeful limitations and optimization.

[Ronald Nyein Zaw Tan]

Hi Colin,

You hit the nail with the posterization comment. I doubt my clients and would "notice" the banding and the point about the contact sheet—as you say—is the rough view for the client to make their selects for me to finalize to their specifications.

Maybe because we an imagemaker, I wanted my images to be best represented and the MWCS's limitations and posterization had me briefly raise a concern.

Thanks for your input. You're right. Most of the time, the client will be focused on they look with my lighting and not banding patterns in the background. :-)

Ron