Colors changing during .dds conversion

[the_dudeWG]

Hi, all.

I can't figure out what is happening, but I've just noticed that with the Flying Circus AD5 template, every .dds file I save, all the colors lighten slightly. This has never happened to me in over 6 years of skinning and I'm totally stumped. It seems to be related to certain templates. So far, I have no issues with the Camel or Dr1 templates, but the AD5, PD3a, FD7, and FD7F templates all lighten the colors when created (that's all I have checked so far). Below is an example using the AD5 template.

 

Notes:

1) I used templates straight from my Downloads folder so as not to use a working template that I may have accidentally changed any settings.

2) Shown in both examples are the color settings for that particular file, with no differences between files.

3) I turned off the Shading and Weathering folders and took a color sample in the center of the crosses as noted by the yellow arrow. The RGB values are very close, yet the CMYK values are different.

 

 

 

If anyone could confirm if this also happens to them I would greatly appreciate it. I know it might seem trivial, but the difference is very noticeable with darker colors and I'm finding it very frustrating. Thanks! 

Edited February 5, 2020 by the_dudeWG

[ZachariasX]

The only way this could  be explained is that there is a color space conversion taking place. Just this question: have you calibrated your output devices?

 

But I see such happening in general when the original file (dds here) is not created in the color space you are using, say Adobe RGB. If you save it to the color space you specified, there will of course be a change as you are observing it.

 

EDIT: the „washed out“ effect I usually observe by projecting an image from a large color space into a smaller color space (like sRGB).

Edited February 5, 2020 by ZachariasX

[the_dudeWG]

9 hours ago, ZachariasX said:

The only way this could  be explained is that there is a color space conversion taking place. Just this question: have you calibrated your output devices?

 

But I see such happening in general when the original file (dds here) is not created in the color space you are using, say Adobe RGB. If you save it to the color space you specified, there will of course be a change as you are observing it.

 

EDIT: the „washed out“ effect I usually observe by projecting an image from a large color space into a smaller color space (like sRGB).

But isn’t my color space shown in the color settings window? They are identical. This is what baffles me. That, and the fact that other templates produce no changes. If there was a problem with my system or PSD settings, it would happen to all .dds files I create. It has to be something in the templates. Cheers!

[ZachariasX]

13 minutes ago, the_dudeWG said:

But isn’t my color space shown in the color settings window?

I don't think so. What your dialogue shows are the color settings of Photoshop, not the picture itself. The picture cannot be both RGB and CMYK. It is either or and the dialogue only makes sense by giving you the option of selecting color spaces for working any kind of content.

 

It is in this "Edit" > "Convert to profile" selection that you can choose different color spaces. Depending on the computer of the one original coming up with the templates, it might even be that by acident "Apple RGB" is chosen as color space of the picture. But this dialogue will not show you that it will show you a seletion of color spaces in which to project your image (and hereby altering it).

 

What Photoshop can do to you is calculate, say CMYK values for any RGB value you are picking as it is displayed in your screens color space. Especially if you have a nice calibrated screen, this is NOT sRGB! Any sRGB picture you are loading on screen does not "have" this CMYK value yet. Only when you do color separation by ad hoc converting what you see on your screen to CMYK and *then* it has CMYK values that are seeing.

 

Usually you get your observed effect by processing JPGs from a camera that develops "Adobe RGB" JPGs instead of "sRGB" JPGs. While this can make sense if you have a very green scene and you want to maintain a larger color variation in those green hues at the expense of congruent color hues shared between the two color spaces. Thus, the total number of colors (8 bit per channel) remains the same, but if you bring in new colors, you have to take some hues from the congruent area of the two color spaces of both Adobe RGB and sRGB. This results in a mild "washing out" of those colors as soon as you save those pictures as sRGB.

 

And I think that this is what you are observing. If the pic is in a different color space than specified in your dialogue, mighty Photoshop converts the colors such that they approximate the color space available on your screen. These are the values presented by using the color picker. Saving the image to your different color space now maps those colors on sRGB. And by doing so it now must approximate every single color value to the next best available in your current color space. This process ("color maniging") obviously alters the colors. What then happens is that those altered colors (upon saving) are again mapped to the larger sRGB color space that you are usng on your screen.

 

Often enough, images are lacking color space info. This is visible across this worlds webpages as soon as you enable your browsers color management system. (Sadly, it is not on by default, but people generally prefer awful settings anyway.) Firefox is somewhat good at that, from there it is downhill to Explorer (surprize!) last time I checked. Then these pictures appear with distorted colors in your browser, usually they end up way too dark in Firefox. Now if a program (and be it Photoshop) CANNOT detect the color space of your image, it just uses defaults. It just assumes any RGB pic being sRGB, and likewhise it uses defaults on CYMK images.

 

So what to do? I suggest that you take a look on the original image to find out what is actually in there. ExifTool is a command line tool that really helps you if you are frequently getting images "from someone" that you invest your time in. It will show you what is in there and by looking up ICC Profile tags, you can see if someone used a different color space than you are using.

 

If that really is the case, then it really is an error by the original designer, as you are only doing sRGB images in computer games. But by saving the image with your Photoshop settings, you do get an image that will work on everyones computer.

 

[the_dudeWG]

@ZachariasX Thanks a ton for all this useful info! It makes much more sense now, and it gave me the idea to research about how PSD handles content created by other users (i.e. all the various FC templates). Here is what I learned ...

 

1) By default, PSD does not notify the user of the color profile of an image when opened. This should be changed, and/or the policies should be changed to "Off" or "Convert to Working ..."

 

Like this ...

 

After turning on the notifications I started receiving the warning message shown below. 

 

2) I've been working in sRGB (as noted by my color settings), and by default every template retained its own color profile. The Dr1 and Camel templates are sRGB, so they played nicely with my PSD settings and the .dds files matched my template. The others are Adobe RGB (1998), so when I created those .dds files, they used my sRGB setting and the resulting .dds files looked different than the template.

 

3) Removing the color profiles from the templates entirely seems to give me more consistent results. I'd be curious to know if most experienced skin creators prefer this method.

 

Anyway, thanks for all your help mate! Cheers!

[ZachariasX]

I‘m glad you found the issue.

 

1 hour ago, the_dudeWG said:

The others are Adobe RGB

Such happens often enough.

 

About how to proceed I cannot really comment as it would depend on your workflow. I had to learn this the hard way and I can only say what works for me so far. Anyone more proficient is very welcome sharing insights.

 

But it is important to know that this

1 hour ago, the_dudeWG said:

3) Removing the color profiles from the templates entirely seems to give me more consistent results.

in essence cannot work as bitmaps (compressed or not) ALWAYS must have a color space assigned to it. Only RAW files from your camera do not have a color space, your computer has to assign them one on order to display them. In essence „developing“ it. If you do not have color space info, your computer throws a wild guess, usually claiming it to be sRGB.

 

If that image is not sRGB or the viewer you are using cannot do color management (usually default web browser setting) the image will be shown in wrong colors.

 

Personally, I always do the conversion manually and save as a new file. If it is an image only to be used on the computer, making it sRGB is the first step. You don‘t want to make it perfect then convert and mess up your hues.

 

Generally speaking, once you go to a narrower color space, you lose colors. As long as you never go back to a larger color space, this is no problem.

 

This is why you work with your images in RGB and once you like them then you convert them to CMYK for printing. After conversion, you check what you got. Usually this should work ok, as the CMYK profile should be supplied with your printer. But on a HP Indigo, SWOPv2 works (PS default) fine for „normal“ prints.

 

It is of note that the printer driver again blows up the print ready CMYK into LAB space (like this it can process about any image) and from there it will do color separation again for the printer. As LAB space is huge and it is done at much higher resolution, you can rather exactly get the original CMYK values back that are set to the individual printer colors.

 

In short, a color space is something everybody has all the time, mostly without knowing it. Your screen has it:

 

On most screens, you can select presets about how the picture looks. A screen usually has a default with a 9300K white, making colors vivid looking at a row of them put on display in a shopping mall. But it is just awful and headache. Also, most screens are not set to sRGB but DCI. You can see in the chart above, that like this they can make greener greens and and deeper greens like that. If you go with this setting, no matter what you do to your sRGB image, it will never be as green as your screen can show. But as we are running on neutered systems, we do have 8 bit colors on the screen as well. This means in the nice looking DCI color space, your sRGB colors will be interpolated and so will be the values of your color picker. If we could set our screen to display 10 bit colors that would just be... awful for the vendors, as a significant value proposition of „pro“ hardware that does 10 bit colors on the same hardware would be negated.

 

As you are doing this for computer games and not printed reference material, this shouldn‘t be an issue. Still, you had to set your screen to sRGB to get an exact impression of your image.

 

 

[Pict]

Interesting stuff.

 

This may or may not be of interest to someone...I have always saved to .bmp then converted outside of Photoshop with an old but far from obsolete tool called DXTBmp by Martin Wright, which along with his other stuff is still available here http://mwgfx.co.uk/

 

================

 

While digging up that link I also spotted a screen grab utility that he did called mgrab that I used to use. I must test it out again and see if it works to take screen shots of the viewer, as that might be handy.

 

Update: Yes after testing I can confirm that works, which is cool as I hadn't managed to do this before now, thank goodness for "old" tech 

 

Edited February 6, 2020 by Pict
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