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overlap -- Overlaps two images in X or Y, by a certain amount of columns or lines.


overlap input1 input2 output dx dy


This task creates a composite 2-D output image from two input 2-D images. The composite is the result of overlapping the two input images by a certain amount of lines or columns. The amount is specified by task parameters dx and dy. If dx>0 and, dy=0, the input images are overlapped columnwise: last dx columns of input1 are overlapped with first dx columns of input2. The input images must have the same number of lines. If dx=0 and dy>0, the images are overlapped linewise, and they must have the same number of columns.

The overlapped region is built as a weighted average of the relevant regions in the input images, and the weight function is specified by task parameter weight. It can be either a linear or a cos tapering function.


input[file name]
First input 2-d image section.
input[file name]
Second input 2-d image section.
output [file name]
Output image. Always type real, regardless of input image type.
dx = [integer, min=0]
Amount of overlap in X direction (pixels).
dy = [integer, min=0]
Amount of overlap in Y direction (pixels).
(weight = "cos") [string, Allowed values: cos | linear]
Type of weighting function used in overlapped region.


1. Overlap in X images image1 and image2 by 100 pixels, using linear weighting:

  pl> overlap image1.hhh image2.hhh output.hhh dx=100 dy=0 weight="linear"



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