Method Detail

• clipRectangle

   static Pix clipRectangle(Pix source, Box box)

  Extract a region from a Pix.

  Notes:

  This should be simple, but there are choices to be made. The box isdefined relative to the pix coordinates. However, if the box is notcontained within the pix, we have two choices:

  (1) clip the box to the pix

  (2) make a new pix equal to the full box dimensions,but let rasterop do the clipping and positioningof the src with respect to the dest

  Choice (2) immediately brings up the problem of what pixel valuesto use that were not taken from the src. For example, on a grayscaleimage, do you want the pixels not taken from the src to be blackor white or something else? To implement choice 2, one needs tospecify the color of these extra pixels.

  So we adopt (1), and clip the box first, if necessary,before making the dest pix and doing the rasterop. But thereis another issue to consider. If you want to paste theclipped pix back into pixs, it must be properly aligned, andit is necessary to use the clipped box for alignment.

  Parameters:

  source - Source pix

  box - Requested clipping region