Enhancement – Stretch

”Stretch” will adjust the contrast of the input image.

A ”linear” stretch will stretch the values of the image pixels between specified minimum and maximum values, and black and white. The output will be the same form as the input, either unsigned integers or floating point numbers. The min and max values can be specified. If left blank, the stretch will be between the min and max values of the input.

”sqrt” and “log” simply take the square root or the logarithm of the input pixel values. The output will be floating point numbers.

“threshold” will output an 8-bit unsigned integer image that has pixel values of either 255 or 0, depending on whether the pixel value is greater than, or less than or equal to, the threshold value, respectively.

Threshold values must be specified. One threshold value must be specified for each input band. Alternatively, one threshold value can be specified for all bands.