USGS MIPS Histeq Documentation

USGS MIPS Histeq Documentation

This program applies a histogram equalization stretch to an image . That is, it will determine the stretch required to make the histogram uniform or have equal counts at each DN . For example,

        ---
     __/   \       -------------
    /       \      |           |
  --         ---   |           |

    Before            After
    Histogram         Histogram

Files

This program requires as input one unsigned 8-bit image file. If an output file is entered, then it will contain the image with the histogram equalization stretch. If an output file is not entered, then a stretch file will be added to the input image and the labels will be updated. The stretch can be applied at a later time by using the program APPLYSTR or can be viewed with the restore stretch option in VISTA.

Parameters

TITLE: This parameter is used to store a title in the stretch file for the stretch pairs required by the histogram equalization stretch. It is only used if an output image is not created.

Uses

This program applies a "high" contrast stretch to an image. It will not work well for images with histograms that are not normal (i.e., bell shaped) because typically large regions are stretched to black and white. However, it will work fine for derivative, shaded relief, or high pass filter images.

Examples

From left to right, an unstretched horizontal derivative, the derivative stretched using the program PICSTR, and the derivative stretched using HISTEQ.

[Example Image]