The Ur-Quan Masters Discussion Forum

The Ur-Quan Masters Re-Release => Technical Issues => Topic started by: Rib Rdb on November 03, 2003, 06:23:03 am

Title: Image Formats
Post by: Rib Rdb on November 03, 2003, 06:23:03 am
Can anyone explain, or point me to an explanation of, the difference between DirectClass and PseudoClass png's, and why 46 of the images in the content directory are PseudoClass?

Title: Re: Image Formats
Post by: Nic. on November 03, 2003, 08:16:47 am
Google told me this:

DirectClass images are continuous-tone images stored as RGB (red, green, blue), RGBA (red, green, blue, alpha), or CMYK (cyan, yellow, magenta, black) intensity values as defined by the colorspace [attribute].      

PseudoClass images are colormapped RGB images. The colormap         is stored as a series of red, green, and blue pixel values, each value being a byte in size. If the image depth is 16, each colormap entry consumes two bytes with the most significant byte being first. The number of colormap entries is defined by the colors [attribute].

I know that in a few places it is important for the game images to use a specific colourmap, which would explain the PseudoClass PNGs, but frankly I'm suprised that there aren't more of them.

Title: Re: Image Formats
Post by: Michael Martin on November 03, 2003, 12:15:38 pm
All the 8-bit images tend to get palette-swapped all the live-long day, just because of the nature of the renderer.  I'd guess that the distinction was just what our various paint programs decided to do.