Custom Splash Screens

[Gare]

I’ve done a little reading/research, and discovered some things about the BMP file format that might be of interest on this thread.

First, I used Photoshop to create a 32-bit BMP. And no, Xara would not load it as the splash screen. But I did learn from the failed attempt.

Xara Designer interprets all alpha channel information when you import a PSD or a TIFF as transparency information. So what’s the diff’ between a PNG with transparency, and a TIFF that is interpreted as having transparency? A PNG is bound by its construction—its definition for as far as I can tell— to be interpreted by most programs as a “single layer RGB channel file with transparency. That is to say that there isn’t any alpha channel to guide Xara to understand where there is transparency.



On the other hand, a TIFF file can have about 32 alpha channels, I think, and in Photoshop at least, you can use an alpha channel to declare where transparency is by the brightness of areas in the alpha channel, or you can use alpha channel info for bump mapping, or displacement mapping…an alpha channel is just an extra set of instructions that maps the color information pixel for pixel.

Technically, and XRGB image is an image that just has an additional channel of (grayscale) visual information, and you see in Photoshop that you have no option if you want to export a BMP with an additional channel: it has to be written XRGB. Which is sort of useless for splash screens because Xara I’m fairly certain by now has no way to know that it should use the extra info as transparency information.

I did find a free program called Pixelformer, and it was happy to write a 32-bit BMP with an explicit alpha channel, attached. It does nothing as Splashscreen.bmp in the way of transparent regions, but interestingly, Photoshop will open it and show you it has an alpha channel.



TIFF, PSD=alpha channel which Xara sees as info about what areas are transparent.

BMP=can hold an alpha channel, but so far only Photoshop will show it and by default will not show transparency around the non-transparent pixels. You have to load the channel as a selection and then copy or cut it to a new layer.

It’s odd, isn’t it, that the programmers are still with BMP as part of the program? Microsoft has moved almost all of their bitmap stuff (icons, splash screens) to PNG years ago. This is not a criticism: I think it’s interesting that some programmers tap into relatively unknown capabilities with file formats. I thought for ages that AVI video couldn’t hold an alpha channel (for green screening and compositing 2 or more videos, like we do with layers), but Adobe After Effects and a few others in the suite will read and write an AVI with an alpha channel. Which means I’m not bound to working with QuickTime if I need to do composite work.

My Best,

Gary