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samsc
23-08-2003, 09:33 AM
Can I use a photoshop image with a transparent background, or with an alpha channel in catalyst?

Yes. It should work.
Alpha channels are supported in photoshop images, and will be transparent. ( Thats how its supposed to be...unless i made a mistake )

RobF
16-12-2003, 04:24 PM
On that subject I found a nice little explanation the other day:


How do alpha channels work? ??An alpha channel is simply a way to use variable transparency with an image. GIF images support binary transparency, which allows any given pixel to be either fully transparent or fully opaque. In contrast, PNG allows up to 254 levels of partial transparency in between these two extremities. ??PNG images are categorized into three types: truecolor, grayscale and palette ? all of which support alpha information. However, alphas are most commonly used with truecolor images. Instead of storing three bytes for every pixel (red, green and blue), files containing alpha information store four bytes per pixel: red, green, blue and alpha, or RGBA. Variable transparency allows you to create visual effects that look good on any background. Another benefit is the use of alpha blending, which allows the use of anti-aliasing to make rounded and curved images that look good against any background. Therefore, images can be reused across numerous compositions, without the ghosting effect that occurs with GIFs. ??Regarding color depth, it is always necessary to use 32-bit color depth (sometimes called ?Millions of Colors+?) to have alpha channel support in your video or graphics. Without 32-bit color depth, which is only available in a small number of codecs, files will not support alpha information. If you select a codec that does not list ?Millions of Colors+? as one of its color depth options, then you will not get 32-bit color depth using that codec.

Spam Butterfly
20-01-2004, 10:20 AM
It's worth remembering that Animation Codec allows an alpha channel.

Spam Butterfly. :) :D

Spam Butterfly
20-01-2004, 10:38 AM
Can I use a photoshop image with a transparent background, or with an alpha channel in catalyst?

Yes. It should work.
Alpha channels are supported in photoshop images, and will be transparent. ( Thats how its supposed to be...unless i made a mistake )

BTW It works great.

SB :p

samsc
20-01-2004, 04:18 PM
It's worth remembering that Animation Codec allows an alpha channel.

Spam Butterfly. :) :D

the animation codec is the only codec i know of that supports alpha channels in movies.

nothing else does.