ListConvolve on TIFF images

*To*: mathgroup at smc.vnet.net*Subject*: [mg77776] ListConvolve on TIFF images*From*: andre <erasmus.the.giant at gmail.com>*Date*: Sat, 16 Jun 2007 03:57:49 -0400 (EDT)

I'm using Mathematica 6 to do some image analysis on a stack of TIFF images saved as a single file. Originally, I was using another program (ImageJ: http://rsb.info.nih.gov/ij/ ) to export each frame as a text file and then importing them into Mathematica and appending them together to make a 3D array. Part of the analysis uses ListConvolve as follows (the image stack has 61 frames and I'm convolving each one with 5 different filters and storing the results in responseArray): For[a = 1, a < 61+1, For[i = 0, i < 5, response = ListConvolve[loGBank[[i]], rawImageStack[[a]], {-1.-1}]; responseArray[[a, i]] = response; i++; ] a++; ] Using imported text images this operation takes a few minutes. Since I don't want to go through the step of exporting the text images using ImageJ, I started importing the TIFFs directly using Import["filename.tif", "Data"]. This seems to work fine and I checked that the directly imported TIFF data are the same as the appended imported text data (i.e. tiffDataArray == textDataArray returns "true"). My problem is that while the above ListConvolve procedure takes a few minutes with the text data, it takes much longer (runs until the kernel quits due to lack of memory) using the directly imported TIFF data even though Mathematica says they're identical. What's wrong?