Alpha channels

[ATV2gal]

Hi,
I would like to know how I can learn how to make the images for the alpha channel. They look transparent but you can load them onto your image and it may have circles, rectangles or square etc that you can fill in with a color.
Thank you for your help.

[LeviFiction]

PSP uses Masks and Selections to work with alpha channels.

To load an alpha channel you can use either Layers -> Load/Save Mask to alpha channel -> Load Mask from Alpha Channel

To load an alpha channel to a selection you can use Selections-> Load/Save Selection to Alpha Channel

You can save them to the same way. Either as an independent mask/selection image on your harddrive. Or as an actual alpha channel inside the image you're working on.

To create an alpha channel you must first either create a mask or a selection. Then save that to the alpha channel.

Be warned, however, some image formats PSP does not properly interact with alpha channels. So when saving an image with an alpha channel, save it as a copy do not save over the original. In some cases PSP will discard the alpha channel entirely, and in others it limits you to one alpha channel, or like in the case of a TIFF file it'll merge the alpha channel and the original image to make it transparent but you lose the image data that was there.

[ATV2gal]

Hi,
Thank you for your reply. If I understand you correctly I can bring up a transparent new image. Make some selection with my selection tool. Then go to Selections and save as alpha selection.
Then I can? Do I do a select none and do a clear and then can go ahead and do say a flood fill etc? Or can I save this image as a PSP file? How do I make several selections on one new image so they show up separately when I save them to the alpha channel?
I hope I am understanding you correctly.
Thank you again

[hartpaul]

I remembered making a post about masks , Selections and Alpha Channels on another forum. I hope this is correct.
First of all thank you for asking the question about Masks and Alpha channels. That and the discussion made me experiment and look into it a bit further. So this is my explanation as tested in X4:

A loaded image appears in your layers palette as a Background layer.
This can be promoted to a full raster layer which can then show transparency (Anything that attempts to produce transparency will automatically promote the layer eg use eraser on background layer ) .

A raster image contains 4 channels - red, green blue and Alpha.
The Alpha channel is like having a folder attached to that image (if saved as pspimage) and you can save many masks and selections into the Alpha Channel as shown:


I don't know if there is a limit to the number of masks and selections that you can save.

I took three images loaded them and then placed two on the third as new layers so I had three layers in the image. I deleted the other two images .
I applied masks to the top two image layers so that various parts of the three images could be seen . I saved the masks to the Alpha channel. I did this with a couple of selections and saved the selections to the Alpha Channel. Then merged all and saved as a pspimage. (the selections and masks are saved with this image)

Cleared the workspace and reloaded that saved psp file. (with its included masks and selections)

Loaded another new image. Then tried to do Layers > Load/Save Mask > Load Mask from Alpha Channel and the masks and selections from the psp image were available for use on the new image.

Same with Selections > Load/Save Selection > Load Selection from Alpha Channel.

As well any mask could be loaded as selection and any selection could be loaded as a mask as they are both just black and white images.


This has opened my eyes to the power of masks, selections and Alpha Channels.
It also mean you could have a folder of images containing different images each with their saved selections and masks as a storage option.

[ATV2gal]

Hi,
Thank you for the great explanation of how this is done. I really appreciate you taking the time to do this.
ATVgal