English

How To: Clip an image

Procedure

Summary

A procedure to clip an image.
Answer:

Procedure

Clipping of images is fundamentally different from clipping coverages. This is
because images are raster data, where as coverages are vector data.

There are several ways to clip an image. The most straightforward way is shown below, followed by two alternate methods.

Method 1: Use the RECTIFY command, specifying a clip BOX or clip_cover on the command line. Note that the clip_cover area is defined by the BND of the coverage, not the polygon features in the coverage.

An image is always rectangular, so it can only be clipped with a rectangular box or BND.

Method 2: If ARC/INFO 7.x or higher is available, convert the image to a grid and use the GRIDCLIP command.

Method 3: This method requires a TIN license. Convert the image to a grid with IMAGEGRID, then clip the grid with the LATTICECLIP command. LATTICECLIP can use an irregular polygon to clip a lattice or grid. The output lattice will still be rectangular (possibly a smaller rectangle), but the lattice cells outside the clipping polygon will have the value NODATA. Convert back to an image if desired with GRIDIMAGE.