Decorrelation stretch
Decorrelation stretch (DCS) is a process that increases the contrast of an image by decorrelating the input bands. In the image above, note how shades of brown are transformed into more vibrant primary colors, highlighting the subtle differences in the original image. Similar to PCA, the algorithm works by computing a linear transformation of the input, but unlike PCA it only works on three input bands at a time.
Tip
More detailed information about DCS with a focus on ASTER processing can be found here.
Usage
The DCS dialog allows you to select the product,
input bands to map to the decorrelated RGB image, and an
AOI for analysis, along with inputting a name for
the result. Click Run DCS to compute the transformation and add it to as a
raster layer in the project.
Warning
Although the transformation will be applied dynamically to the layer, keep in mind that it was computed over a specific AOI, and the variance and loadings are only valid over the input AOI. If you are moving to a new geologic regime, it is often necessary and wise to recompute the transformation in the new area instead of relying on the original statistics.