Alpha transparency difference PS and Firefox

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1

Hello everyone!

I’m not sure I understand everything I’m doing here and that’s why I’m asking for your help :slight_smile:

In Photoshop CS5, I have a simple shadow with alpha transparency on it.

  • When I put a white background and when I use a color picker on a certain part of the image, it gives me, let’s say, #DADAD9
  • When I export the image using “Save for web” and open it in Firefox/IE8/Safari/Chrome/Windows viewer on a white background, that certain part gives me #DAD9D8
  • If I open the file back in Photoshop and assign it a white background, it gives me #DADAD9 again.

I’ve tried every color profile setting possible.

Is there a difference in the way PS and the others blend the transparent color with the white background?

Thanks! :smiley:

2

It might just depend where you are clicking on the image. Each pixel might give a slightly different result, given that it is a shadow.

3

It wouldn’t be surprising if each browser interpreted the blending slightly differently.

-Michael

4

Actually I have run into this problem myself. PS embeds a whole bunch of info ( file bloat) in the form of color profiles. Some browsers read this and make correction some don’t . For example the same graphic probably appears fine in Safari or Chrome! If this is the case Try either of these methods and see which one is preferable to you.

  1. make sure you have convert to sRGB checked.
    2)you could use a utility like ImageAlpha to not only make the file smaller but get rid of the annoying extra data.

this will help your colors MATCH within the same screen. but the way each UA and platform interprets color varies , as does with the OS, and sometimes even just the monitor itself.

5

Hello all and thank you for your answers!

@ralph.m : No, each horizontal line is one color and I pick the top line so no mistake there.
@eruna : Yep, that may be it, unfortunately
@dresden_phoenix : I had already tried with sRGB on and off, by disabling color profiles, by using RGB proof model, by using pngout to disable all extra data in the file. Nothing…

6

PNG also has a gamma parameter that is supposed to correct the image to look right on different monitors. It frequently causes color matching problems. There is no way to remove it in Photoshop, but you can find software to strip it out.

E

7

PNG also has a gamma parameter that is supposed to correct the image to look right on different monitors. It frequently causes color matching problems. There is no way to remove it in Photoshop, but you can find software to strip it out.

This is why I suggested using a utility like ImageAlpha.