Why does ImageCompose degrade the result and can you do anything

*To*: mathgroup at smc.vnet.net*Subject*: [mg98469] Why does ImageCompose degrade the result and can you do anything*From*: Bob F <deepyogurt at gmail.com>*Date*: Fri, 10 Apr 2009 04:56:01 -0400 (EDT)

I wanted to play around with one of the new version 7 image routines, called ImageCompose[], which can be used to add images together. When I was trying to use it, the resultant image was a much degraded image for some of the examples I was playing with, compared to the originals (looked like the resolution was significantly less than the originals), so when you change the magnification the resultant image gets worse and worse and worse as you increase the magnification. Especially noticeable was the text on the tick labels, and the jaggies in the curves and the rasterization becomes more and more prominent, even though the original images don't show this. So, anyone have an idea of why ImageCompose does this and is there a way to use it to add two images together and have the result be as good as the originals, as long as the two have the same resolution? Here is an simple example that shows what I mean: i1 = Plot[Sin[x], {x, -3 Pi, 3 Pi}] i2 = Plot[Cos[x], {x, -3 Pi, 3 Pi}] ImageCompose[i1, i2] So if you up the magnification the ImageCompose version gets more and more jaggies, as well as the axes and ticks and tick labels getting worse and worse. Thanks... -Bob