OUTPUT data format.
VALID = BYTE or HALF.
A border pixel is a pixel whose data number is greater than or equal to the value specified for the BORDER parameter. The default BORDER value is 255 for byte-data images and 32767 for halfword-data images.
This option allows borders to be painted over. For each border pixel a neighboring region is selected at random, and the data number for that region is assigned to the pixel. (The random selection is used so that this process increases the size of regions in a statistically balanced way.) If there are no non-border pixels within five pixels of the border pixel in the same line, the line above, or the line below, a zero data number is assigned to the border pixel.
If both the THRESH and PBORD options are used, regions smaller than the threshold size are assigned the data number for a larger neighboring region.
If ZEDGE is not specified, regions may have the edge of the image for a border. If ZEDGE is specified, regions may not have the edge of the image for a border.