GIMP Version: 2.8.2
Operating System: Windows
OS Version: XP - SP3
GIMP Experience: Beginner Level
URL or Image link: http://en.celebrity-speakers.de/static/img/slidebar/garry-ka

---

Hello!
Doubt arose now.
Was downloading an image (transparent .png) and on the website it appears as if the white background (until then normal).
But when I use the copy option and open the Gimp (File> Create> From Clipboard) transparency is lost! The background is black.
To avoid losing the transparency of the image in Gimp, I needed to download it to my HD (hard Driver) and then open it with Gimp.
Was this a bug or am Gimp with some setting wrong?

Thx.

Apparently it's not due to firefox (last stable build), nor gimp (2.6), I tested with your avatar. I believe it's a png settings issue, each png image has its own settings embedded, like color space, color profile, background transparency and so on.
Have you tried to save the image regularly (no clipboard) ?

Your link is 404 BTW.

Oh and for the sake of accuracy, here is a portable tool I use to edit unwanted png settings:
tweakpng - http://entropymine.com/jason/tweakpng/
Beware though as editing critical datas crushes your image, so edit a copy to be sure.

Hi anarkhya,

Yes, I saved on my hard disk, and thus transparency was preserved.
The link appears to be definitely 404. In any case, is below the image.


I appreciate the feedback and indication of tweakpng portable.
Thank you very much!

P.S: Try yourself : File> Create> From clipboard in Gimp, the above image.

It appears so in my Gimp. Without transparency, and the black background.

Hi, Akros!
I think the problem is the browser's clipboard API, which is somehow not supporting transparency. Just curious, what browser do you use and what version?
I tried with chrome and ie and their clipboards seem to not support transparency. I don't think it's GIMP. The same thing is happening with Inkscape and PS.

BTW, is that a picture of Gary Kasparov?

What you are doing is a basic 'copy visible' you will not retain embedded settings, such as transparency, unless you download the source image. This is not a bug or a limitation of the applications, only the method.

Thanks, Odin!
Your simple explanation clarifies everything! Never crossed my mind that it's the same as 'copy visible'

What is not clear yet, why it assigns black bg color. Not white, not any arbitrary opaque color.

copy the image location & have gimp open the location.

File/Open Location

Yeah! That works!

This is correct.

According to the image comment ("Image->Image Properties"), the file was created with GIMP. When you export to the PNG file format, one of the options is "Save color values from transparent pixels". If this option is disabled then GIMP will replace all fully transparent pixels with the current background color. This color is never seen (the pixel is transparent), but making them all the same color usually helps in compressing to a smaller filesize.

You can test this with the following:

• Load a JPEG file
• Add an alpha channel to the layer.
• Perform an "Edit->Clear" (the layer becomes transparent).
• Export to a PNG file with the "Save color values from transparent pixels" option checked.
• Load the saved PNG file (the image should still be transparent).
• Perform "Layer->Mask->Add Layer Mask" with the 'Initialize Layer Mask To' option set to "Transfer layer's alpha channel".
• Delete the layer mask (your original image is restored).

Now repeat the above with a red BG color and with the "Save color values from transparent pixels" option unchecked (the result should be a solid red image).

Hi guys!

K1TesseraEna wrote:
Just curious, what browser do you use and what version?
Chrome Versão 24.0.1312.56 m
K1TesseraEna wrote:
BTW, is that a picture of Gary Kasparov?
Yes it is!

Odin wrote:
What you are doing is a basic 'copy visible' you will not retain embedded settings, such as transparency, unless you download the source image. This is not a bug or a limitation of the applications, only the method.
Thx Odin, how i don't speak english, is hard to me find words to say, then i will to use the same as KiTesseraEna, cause would be what i would like to say:

Your simple explanation clarifies everything! Never crossed my mind that it's the same as 'copy visible'
What is not clear yet, why it assigns black bg color. Not white, not any arbitrary opaque color.

ico4498 wrote:
copy the image location & have gimp open the location. File/Open Location

Thanks ico4498, not yet tested, but KiTesseraEna said works. I'll check it out!
Edited: Yes that work! Thx!

saulgoode thx, i will try do it now!

Thank you all for your attention to this question!

Wow saulgoode, this is witchcraft!
A transparent image appears out of nowhere! Incredible.
That would explain how the image was saved. ("Save color values ​​from transparent pixels" option unchecked)

But what is not clear yet, why in this case the transparency is not recovered? The black background does not disappear, even following steps:

Perform "Layer->Mask->Add Layer Mask" with the 'Initialize Layer Mask To' option set to "Transfer layer's alpha channel".
Delete the layer mask (your original image is restored).

@Akros:
It may help if we put some facts on the table, you may already know them or some of. Usually an image without transparency (=without alpha channel) is RGB, in RGB color space, for each pixel in your image you have 0 to 255 possible values of R (Red), 0 to 255 possible values of G (Green) and 0 to 255 possible values of B (Blue) so each pixel is given an R*G*B value, so, for instance, a fully saturated red pixel is 255R 0G 0B. This is the case for jpg image.

Now when transparency is added to the mix, your RGB image gets another channel it's the A (Alpha) so you get an R*G*B*A* image with, for each pixel, also 0 to 255 possible values of Alpha (Opacity), this is the case for png images, however for gif images there are only 2 possible values, a pixel is either 0 or 1 (opaque or transparent).

Sorry if I brought some already known facts (:

Hi anarkhya!

Very enlightening! Placed thereby becomes clearer understanding. I believe that others will also benefit from all this.
Thx very much!