Re: Exporting Density Plots -- one pixel per point?

*To*: mathgroup at smc.vnet.net*Subject*: [mg64362] Re: [mg64344] Exporting Density Plots -- one pixel per point?*From*: "Maarten van der Burgt" <maarten.vanderburgt at icos.be>*Date*: Tue, 14 Feb 2006 01:31:38 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hallo, The following results in a gray scale TIFF file which is exactly 3000 x 3000 pixels. The Export to the hard disk takes 0.7 sec on a Pentium M, 1.6 GHz, 500 Mb portable PC with Mathematica 5.0 and Windows XP. Hope this helps, Maarten w=3000; h=3000; dat = Table[Random[Integer, {0,255}],{h},{w}]; gr =Show[Graphics[Raster[dat,{{0,0},{w,h}},{0,255}]], PlotRange\[Rule]{{1,w},{1,h}},ImageSize\[Rule]{w,h}, AspectRatio\[Rule]Automatic,DisplayFunction\[Rule]Identity] Timing[Export[CurDir[]<>"image.tif", gr, "Tiff"]] "quintessentialk" <quintessentialk@ To: mathgroup at smc.vnet.net gmail.com> cc: Subject: [mg64362] [mg64344] Exporting Density Plots -- one pixel per point? 13/02/2006 09:15 Hello, I wish to generate large bitmaps (tiffs, say) where each the greyscale color value of each pixel is determined by a given function of x and y. By large, I mean more than 9E6 pixels. I've tried using a density plot for this, and then a rasterized table, but I run into a couple of difficulties. First, if I use pixel counts which approach this order of magnitude, I get memory errors -- on a win32 machine with 2GB installed. Second, if I make do with a smaller pixel count, I have trouble exporting the plot in a truly one-pixel-per-data-point fashion. (The process is time consuming, and results are unconvincing). I think the problem is the way Mathematica internally tries do everything in a resolution independent way, which I don't want here. Ideas? Questions? (The specific application is to generate high resolution print-outs of holographic patterns which can later be imaged to photographic film. After appropriate development and bleaching, the exposed film can be used as a transmission hologram to couple gaussian laser beams into other interesting modes.) Thank you.