ImgSiz = iwidth, iheight, bpp {,fit, stretch, scaleq, discrete}
Specifies the maximum image size, along with the desired image depth and scaling options.
iwidth and iheight are numeric pixel counts for the maximum size image. If the XTF_VARY bit is not set in the flags parameter, then all images must be the same size. (In this case, XTREE will create an "image list" internally, which is the most efficient way to handle a lot of images.) Otherwise, the row height will vary with the actual image height, up to the maximum specified.
bpp specifies the desired bit depth (bits per pixel), which is used as a clue to the various image loading, conversion, and display routines. Supported values are 1, 8 and 24. If in doubt, set it to 24, which will give the best visual results—at a possible cost in memory usage. With 8, you may see some color substitutions leading to a posterization effect. With 1, you would get monochrome.
The fit and stretch options apply only when the row height (and image size) is variable—i.e. the XTF_VARY bit is set in the flags parameter. Fit causes images that are smaller than the maximum size to be enlarged until they hit the maximum width (iwidth) or height (iheight). Stretch is similar but stretches the images as needed so that they match both the iwidth and iheight values. When XTF_VARY is not specified, the stretch option is automatic.
Scaleq selects a scaling algorithm (bilinear interpolation) which is somewhat slower but generally gives higher quality results than the default scale algorithm.
Discrete causes the images to be stored individually rather than as an internal "image list". This is mostly just a subtle technicality, but is required for icon images when the XTF_VARY option is not specified.
Examples:
ImgSiz=133,100,24,Fit
ImgSiz=75,50,8,Stretch,Scaleq
ImgSiz=16,16,24,discrete
