Precise bitmaps

*To*: mathgroup at smc.vnet.net*Subject*: [mg96689] Precise bitmaps*From*: "Diamond, Mark" <dot at dot.dot>*Date*: Sat, 21 Feb 2009 19:37:11 -0500 (EST)

A question was asked back in 2005 about precise bitmaps. I have a similar question with regard to Mathematica version 7. Looking at the new image-manipulation functions in V7, I expected this to be quick ... I'd like to be able to create a series of stimuli for use in an experiment. The first step in creating the stimuli is to create a 512 x 512 greyscale image with a white background and which contains the drawn objects. I tried the following to create a JPEG image with dimensions 128x128 ... circ=Graphics[Circle[{0,0},62]] rasterCirc=Rasterize[circ,RasterSize->{128,128}] Export["circle.jpg",rasterCirc] but instead the image dimensions are 360 x 363 pixels. I had also hoped that I could obtain an antialiased arc but the only antialiasing option seems to be for Style, which then produces a non-Graphics object. Can anyone see a simple (i.e., not very low-level programming) solution to the problem within Mathematica? What have I missed conceptually that would explain the 360x363 pixel dimensions instead of my expected 128x128? And is there a way to obtain the anti-aliased circle? Cheers, Mark Diamond