The source and the destination images will occupy the same region of the plane. A given destination pixel (x, y) may be computed from the neighborhood of source pixels beginning at (x - leftPadding, y - topPadding) and extending to (x + rightPadding, y + bottomPadding) inclusive.
Since this operator needs a region around the source pixel in order to compute the destination pixel, the border destination pixels cannot be computed without any source extension. The source extension can be specified by supplying a BorderExtender that will define the pixel values of the source outside the actual source area.
If no extension is specified, the destination samples that cannot be computed will be written in the destination as zero. If the source image begins at pixel (minX, minY) and has width w and height h, the result of performing an area operation will be an image beginning at minX, minY, and having a width of w and a height of h, with the area being computed and written starting at (minX + leftPadding, minY + topPadding) and having width Math.max(w - leftPadding - rightPadding, 0) and height Math.max(h - topPadding - bottomPadding, 0).
A RenderingHints for JAI.KEY_REPLACE_INDEX_COLOR_MODEL with the value of Boolean.TRUE will automatically be added to the given configuration and passed up to the superclass constructor so that area operations are performed on the pixel values instead of being performed on the indices into the color map for those operations whose source(s) have an IndexColorModel. This addition will only take place if a value for the JAI.KEY_REPLACE_INDEX_COLOR_MODEL has not already been provided by the user. Note that the configuration Map is cloned before the new hint is added to it. Regarding the value for the JAI.KEY_REPLACE_INDEX_COLOR_MODEL RenderingHints, the operator itself can be smart based on the parameters, i.e. while the default value for the JAI.KEY_REPLACE_INDEX_COLOR_MODEL is Boolean.TRUE for operations that extend this class, in some cases the operator could set the default.
@see BorderExtender
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