The listed image formats should not produce any difference since they all are lossless compressions. You can verify creating images in different formats, loading in J and then subtracting the values.
Regarding image recognition, although the simple difference minimum method may work, it is not very stable and depends on accuracy of defining the kernel and the chosen threshold, which is different for every instance. It would be nice to see how other methods fair, such as cross-correlation, as listed by Devon McCormick http://www.jsoftware.com/pipermail/general/2007-March/029123.html You can go iteratively, tweaking a working algorithm with different ideas to see what's improving. For example, I like the idea of normalization (first link) http://www.owlnet.rice.edu/~elec431/projects96/pictomaniacs/previous.html You can apply it to the method you use now to see if it will eliminate the mismatch. --- Bj�rn Helgason <[EMAIL PROTECTED]> wrote: > When extracting an image to work with from a Dicom file I have three options > > dcm2pnm - Convert DICOM images to PPM/PGM, PNG, TIFF or BMP > > +obt --write-24-bit-bmp > write 24-bit truecolor BMP > > +ot --write-tiff > write 8-bit (monochrome) or 24-bit (color) TIFF > > +on --write-png > write 8-bit (monochrome) or 24-bit (color) PNG > > > I have up to now used bmp and am reasonably happy with the results. > > I am wondering if the other forms TIFF or PNG would give me better results. > Would I need different technique to find the object I am looking for in the > image? > > The method Oleg sent in earlier finds the object most of the time in the BMP > images. > Actually only found one image so far where it missed the object and gave > another fairly similar looking location. ____________________________________________________________________________________ We won't tell. Get more on shows you hate to love (and love to hate): Yahoo! TV's Guilty Pleasures list. http://tv.yahoo.com/collections/265 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
