Bugs: dmimgpick

Bugs

1. Non-square input images (30 Mar 2007)
   (Linux and Mac OS X platforms)

Bugs

1. Non-square input images (30 Mar 2007)
   (Linux and Mac OS X platforms)

   If the input image is not square, dmimgpick exhibits a problem related to how the tool checks if the pixel being "picked" is outside the image.

   While the tool will sometimes fail with a segmentation fault, it may also silently produce incorrect results for non-square images on these platforms.

   Here are the conditions which trigger the bug. Knowing that

   • (x0,y0) is the starting pixel location (e.g. bottom left corner in ds9)
   • xlen is the number of columns
   • ylen is the number of rows
   • (x,y) are the coordinates in the input table for each row

   if ylen > xlen

   all (x,y) where y > (y0+xlen) will have NaNs instead of being joined to correct values

   if ylen < xlen

   all (x,y) where y > (y0+ylen) && y < (y0+xlen) will access random memory and will result in random results including but not limited to the possibility of crashing