How do I create images like this with paint.net?

[game_freak]

If I turn the alpha all the way down in one layer, it works. There is a hidden picture.

If I try to save it.. it gets deleted.

Any ideas?

[MJW]

Assuming I understand what you mean, conceptually, it's very simple: If a pixel's alpha is 0, the RGB color can be anything. So transparent pixels can contain any picture you want. Practically, it's slightly complicated, because lots of methods of making pixels transparent set the RGB color to a specific value; usually white. Fortunately, dpy's Color>Alpha_to_0 plugin only changes alpha.

 

To make a picture with a hidden image, you can:

 

Start with a picture with both a non-hidden and a hidden image.

Select the part you want to make hidden.

Run the plugin Color>Alpha_to_0

 

 

[game_freak]

I get how it works but I can't save them.

Even if I try to save the original it breaks. I assume it's optimized to delete the area where alpha is zero because you wouldn't normally want it anyway.

Spoiler

 

 

 

Edited November 14, 2016 by game_freak

[IRON67]

If transparency is involved, you must save it as PNG. Maybe - if you have worked with multiple layers - you've choosen the wrong blend mode before you merged layers down...

Edited November 14, 2016 by IRON67

[game_freak]

All of the images I've posted have been PNG.

[MJW]

As Iron67 says, they must be saved as PNG, or perhaps some other lossless format. I wondered if PNG would preserve the colors of transparent pixels, since it could conceivably view all transparent pixels as equivalent. I tried it, and the colors were preserved.

[IRON67]

3 minutes ago, game_freak said:

All of the images I've posted have been PNG.

 

You were to fast. I've just added a line.

Edited November 14, 2016 by IRON67

[MJW]

If you write it to a file from PDN, then restart PDN and read it back in, does the hidden image remain? It did when I tried it. However, when I uploaded my test image to PhotoBucket, the PhotoBucket version did not have the hidden image. All the transparent pixels were black when made opaque. Perhaps the same thing is happening to you.