Color Management: HEX value colorshift TIFF to JPEG

[ColorShift]

Looking for assistance with a color shift when saving TIFF to JPEG.

Photoshop color space is sRGB. Document is a TIFF sRGB 500px by 500px with a background fill: d8d4d9. When saving a jpeg, the color shifts to d9d4da when I reopen the file in Photoshop. Is there a setting I am missing somewhere to preserve the exact HEX value?

Settings when saving the JPEG: Quality 12 Maximum, Format Options: Baseline ("Standard").

[Shoku]

Re: HEX value colorshift TIFF to JPEG

Created a tif file, filled with HEX color, and saved as jpeg.

No Changes to color.

Are you doing anything else besides saving to jpeg?

What color settings are you using?

[ColorShift]

Re: HEX value colorshift TIFF to JPEG

Thanks for the reply Shoku.

Did you open the jpeg that was saved and confirmed the HEX color in the file did not shift after opening in Photoshop?

I am using sRGB color setting.

[Shoku]

Re: HEX value colorshift TIFF to JPEG

Did you open the jpeg that was saved and confirmed the HEX color in the file did not shift after opening in Photoshop?

Yes. I created a blank tif, filled it with the HEX color, saved it, then saved the jpeg. Opened the jpeg and the colors are the same - no change.

[ColorShift]

Re: HEX value colorshift TIFF to JPEG

Can you wetransfer me the files you tested, tiff and jpeg?

[ColorShift]

Re: HEX value colorshift TIFF to JPEG

Yes. I created a blank tif, filled it with the HEX color, saved it, then saved the jpeg. Opened the jpeg and the colors are the same - no change.

Can you wetransfer me the files you tested?

[Shoku]

Re: HEX value colorshift TIFF to JPEG

Can you wetransfer me the files you tested, tiff and jpeg?

I was mistaken. If the jpeg is left open it continues to display the same values. Once closed and then opened again, the values change. I double-clicked on the saved jpeg on my desktop but the file was still open in PS - dumb mistake.

Saving to PNG, PSD, BMP, Targa, keeps the color values. Jpeg 2000 changes. So it must due to the jpeg format.

[ColorShift]

Re: HEX value colorshift TIFF to JPEG

I was mistaken. If the jpeg is left open it continues to display the same values. Once closed and then opened again, the values change. I double-clicked on the saved jpeg on my desktop but the file was still open in PS - dumb mistake.

Saving to PNG, PSD, BMP, Targa, keeps the color values. Jpeg 2000 changes. So it must due to the jpeg format.

Thanks for the update. I also read some old posts on Adobe forums and it does not seem possible with jpeg: https://forums.adobe.com/thread/1282796

[John Wheeler]

Re: HEX value colorshift TIFF to JPEG

Hi Colorshift

Maybe more correctly stated, it is not possible with the maximum JPEG setting on Photoshop. The actual JPEG specification has many parameters that can be set which produces trade offs on quality and file size. The particular combination of settings that Adobe used for the 12 setting in PS does not exactly preserve the RGB values even in a field that starts as exactly the same value for every pixel (at least for some values).

I would have to ask why would that matter? If you look at the Lab values in 16 bit mode for the before and after values that you see and calculate the delta E value (a good proxy for observable color difference), it comes to a value of 0.61. For the eye to perceive any difference you need to have a value somewhere between 1 and 2. So as far as the eye can tell, you should not be able to tell the difference.

So is there a real need here or is this just an academic discussion that JPEG does not exactly preserve the exact RGB numbers? Just my quick thoughts.

[ColorShift]

Re: HEX value colorshift TIFF to JPEG

Hi Colorshift

Maybe more correctly stated, it is not possible with the maximum JPEG setting on Photoshop. The actual JPEG specification has many parameters that can be set which produces trade offs on quality and file size. The particular combination of settings that Adobe used for the 12 setting in PS does not exactly preserve the RGB values even in a field that starts as exactly the same value for every pixel (at least for some values).

I would have to ask why would that matter? If you look at the Lab values in 16 bit mode for the before and after values that you see and calculate the delta E value (a good proxy for observable color difference), it comes to a value of 0.61. For the eye to perceive any difference you need to have a value somewhere between 1 and 2. So as far as the eye can tell, you should not be able to tell the difference.

So is there a real need here or is this just an academic discussion that JPEG does not exactly preserve the exact RGB numbers? Just my quick thoughts.

Thanks for your reply! My client's webpage is designed with the specific HEX value where the images I am delivering live side by side. They have flagged the issue after images were populated into their layout. Each image's bounding box is quite visible against the webpage HEX value.

My work around thought was to test delivering .pngs with transparency to avoid the need for HEX accuracy with the jpegs.

[John Wheeler]

Re: HEX value colorshift TIFF to JPEG

Thanks for your reply! My client's webpage is designed with the specific HEX value where the images I am delivering live side by side. They have flagged the issue after images were populated into their layout. Each image's bounding box is quite visible against the webpage HEX value.

My work around thought was to test delivering .pngs with transparency to avoid the need for HEX accuracy with the jpegs.

The client is King so I now understand you issue. I think you have a good workaround. I will poke around and see if there is another easily accessible JPEG converter that will do a better job.

Do you use a Windows or Mac machine? Not all options are supported on both.

[John Wheeler]

Re: HEX value colorshift TIFF to JPEG

The client is King so I now understand you issue. I think you have a good workaround. I will poke around and see if there is another easily accessible JPEG converter that will do a better job.

Do you use a Windows or Mac machine? Not all options are supported on both.

No luck with other JPEG options. IrfanView had the least compression including an option to avoid subsampling yet found out that even with the option checked, the chroma channels still had sub-sampling applied. I concluded other workarounds would be better at this point such as your approach with PNGs.

However, another option if you client accepts them is a JPEG with a Clipping Path. That is a very common way to have a JPEG file with an effective embedded mask (its actually a Vector Path) so the image overlays with whatever the background is on the web page. Clipping paths are supported in Photoshop so thought I would mention this option.

[andrewrodney]

Re: HEX value colorshift TIFF to JPEG

I'm in total agreement with John. Examine the Lab values; that's what counts. You're probably seeing differences in RGB values due to rounding errors from creating the JPEG. What counts is the Lab values or, viewing the original and new JPEG in a color managed app like Photoshop and confirming they both show the same color appearance.