Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
IDLgrImage drawing performance with IDLgrPalette
I stumbled upon this curiosity today and was wondering if I'm doing something wrong or if this is an "IDL thing" I have found that IDL is very slow at drawing indexed color images that use palettes to an RGB device. Or at least it is very slow using my approach. I generally use true color images so maybe I am missing something... Consider the following: pro test_palette ; read some image data, along with palette imgData = READ_PNG(FILEPATH('africavlc.png', $ SUBDIRECTORY=['examples', 'data']), r, g, b) imgDims = SIZE(imgData, /DIMENSIONS) ; create the image object w/o a palette and add to a model oImg = OBJ_NEW('IDLgrImage', imgData) oMod = OBJ_NEW('IDLgrModel') oMod -> Add, oImg ; create a view and window oView = OBJ_NEW('IDLgrView', VIEWPLANE_RECT=[0,0,imgDims[0], $ imgDims[1]]) oView -> Add, oMod oWin = OBJ_NEW('IDLgrWindow', DIMENSIONS=imgDims) ; time drawing this image t0 = SYSTIME(/SECONDS) for n=0, 5 do oWin -> Draw, oView print, SYSTIME(/SECONDS) - t0 ; Add a palette to the image object oPalette = OBJ_NEW('IDLgrPalette', r, g, b) oImg -> SetProperty, PALETTE=oPalette ; time drawing image with palette t0 = SYSTIME(/SECONDS) for n=0, 5 do oWin -> Draw, oView print, SYSTIME(/SECONDS) - t0 OBJ_DESTROY, [oWin, oView, oMod, oPalette] end And the output: IDL> test_palette 0.00000000 27.626000 I had to cut the iterations down to 5 because I didn't have the patience to sit thru the second test. What am I missing? IDL> print, !version { x86 Win32 Windows Microsoft Windows 6.1.1 Oct 11 2004 32 64} -Rick