GIMP Alpha Channel packing

If you google for "GIMP grayscale alpha", the first result is this:

https://graphicdesign.stackexchange.com/a/8943/66143

2 hours ago, Cultusfit said:

Any one familiar with this in this program and able to help me out? I would appreciate it. I know you cant draw directly on the Alpha, you have to use a mask, so i assume i'm over looking how to just pull the image in as the mask?

Under Layers -> Mask -> Add Layer Mask : Select "White (Full Opacity)"

Your layer in your layer tab will now have a second image next to it. Select the second image, this is your mask. Copy and paste your grayscale image into that mask.

Clicking on the layer on the left will allow you to edit the original image, clicking the mask on the right allows you to edit the mask.

There is also a channels sub tab , here you can select any single channel and work with it, by clicking the "eye" icon to hide other channels and not to affect them:

If you don't see these sub tab go to Dockable Dialogs and select what you want from the options. As you can see in the image I keep my Layers tab and Channels tab right next to each other, as I use them a lot.

Remember to export as a image type like PNG that supports alpha.

On 7/29/2018 at 11:48 AM, Kryzon said:

If you google for "GIMP grayscale alpha", the first result is this:

https://graphicdesign.stackexchange.com/a/8943/66143

I promise I googled things LIKE that just not exactly....I kept trying "gimp channel packing" and such.

It's how I found this site. Should have just went simple...ugh.

On 7/29/2018 at 12:15 PM, Scouting Ninja said:

Under Layers -> Mask -> Add Layer Mask : Select "White (Full Opacity)"

Your layer in your layer tab will now have a second image next to it. Select the second image, this is your mask. Copy and paste your grayscale image into that mask.

Clicking on the layer on the left will allow you to edit the original image, clicking the mask on the right allows you to edit the mask.

There is also a channels sub tab , here you can select any single channel and work with it, by clicking the "eye" icon to hide other channels and not to affect them:

If you don't see these sub tab go to Dockable Dialogs and select what you want from the options. As you can see in the image I keep my Layers tab and Channels tab right next to each other, as I use them a lot.

Remember to export as a image type like PNG that supports alpha.

Thanks!

I was following some other directions to add the mask through a different tab and wasn't getting that second window, only a small highlight box that didn't even fill the screen. It was doing weird things. I think I may have been adding a mask to a selected area only or something.

I usually use paint.net so this is all bit different to me. Appreciate the help and images.

I'm curious why the color channels aren't get scale too? Usually everything I've seen works that way. When I just select then they show in that color. Is it just a visual thing?

1 hour ago, Cultusfit said:

I'm curious why the color channels aren't get scale too? Usually everything I've seen works that way. When I just select then they show in that color. Is it just a visual thing?

I assume you meant to ask why the color channels aren't transparent? Your wording here is confusing because scale is how big a image is.

Gimp shows data like a computer will read it. For example a white image is: (1,1,1,1) For every pixel. Meaning (Red ,Green , Blue, Alpha). So even if a image has no or very little alpha, it can still have data: (0,1,0,0) this means each pixel is green, but invisible.

This kind of thing is very important for CGI effects (like green screen) and games. So Gimp shows the user how the computer sees the image.

I hope I understood your question correctly.

4 hours ago, Cultusfit said:

I promise I googled things LIKE that just not exactly....I kept trying "gimp channel packing" and such.

It's how I found this site. Should have just went simple...ugh.

No problem bro, I had thought you didn't search.

@Scouting Ninja I think his "get scale" was an autocorrect from grayscale. Autocorrect can really make you eat the scary bed