PSP - Where is my alpha channel???

[Totoro]

Hello PSP-giants and genius' out there I have a strange problem about Paint Shop Pro...
I have an image which contains a transparent background (I think its transparent, because the check-board-pattern is showing up) and I use the export-png-optimizer-function, where I set "alpha channel transparency" with "existing image or layer transparency". But the new created image does not have an alpha channel... it does not recognize any alpha channel transparency in AGS and I cannot load a selection from alpha channel in PSP either, so I must be doing something wrong @.@ Does someone know what I am doing wrong?

[shbaz]

I thought AGS recognized pink as the alpha channel.

[Nacho]

well... If the alpha channel means setting the "transparency" of a sprite, I think AGS has severall ways to choose the colour.

One of them is to select "top left" or "bottom left" or something... That's the way I use, putting a magenta pixel in the corner of the sprite.

Hope it helps.

[Totoro]

Thank you, but I was referring to the alpha-channel or alpha-blending support feature, so it has nothing much to do with magenta, but with several levels of transparency. I made it work now, although I still cannot select the alpha channel in PSP, but who cares now?
Thank you both for answering

[Nacho]

Excuses for not being very useful... while I consider myself not a bad artist, I recognise that 90% of the people has more ideas of the PSP tecniques than me...  

[BOYD1981]

alpha channels are located under the "Masks" menu, any layer that has/is being used as a mask will have have a little mask icon next to the name in the layer palette

[Ryukage]

First of all masks have nothing to do with alpha channels whatsoever, except that masking a layer creates layer transparency, which PSP can then convert to an alpha channel.  But masks do a lot more than just add alpha transparency, they also affect drawing and blending.

Second, the Load/Save alpha channel feature in PSP has nothing to do with real alpha channels.  It's just a means of storing a mask or selection in the PSP file itself instead of on a disk.  Saved alpha channels are lost when you save as anything other than a PSP file, and the alpha channel stored in a PNG files does not count for the Load Mask/Selection From Alpha channel function.

What everybody else calls an alpha channel, PSP calls "Layer transparency."

So, if you're seeing the checkerboard background, and you select the PNG exporter, and set it to use existing image transparency, then you ought to get an alpha channel.  You won't be able to "load selection from alpha channel" or anything like that, because as I explained PNG alpha is unrelated to PSP alpha.  However, re-opening the image in PSP, you should still see transparent areas, since PSP equates PNG alpha to layer transparency.

The only thing I can think of is that you might trying to export a 256-color image with an alpha channel.  PSP8 prohibits this because it's an invalid combination, but older versions might have allowed it and just dropped the alpha.

In the PNG optimizer dialog, check the preview picture (the one on the right) and make sure the checkerboard pattern shows there.  If it does, then PSP ought to be exporting an alpha channel for you.  Also don't click buttons too fast, PSP needs a second or two to save a temporary version of the converted image each time you change a setting.

[Totoro]

Thank you Boyd. And thank you Ryukage, what you explained to me really makes sense for me now. Arigato ne ...

[TerranRich]

With my PNG files, PSP wouldn't save them correctly until I used the Optimizer Wizard, so try that out, once you feel you've done all you can with the Alpha Channels.

[BOYD1981]

that alphas are only lost if you save in a format which doesn't support them