Typical Contrast Stretching (Auto Levels or Auto Contrast in Photoshop) interatively analyze an image to find the brightest and dimmest pixels (in greyscale). However, an otherwise dark image with one bright spot will span the entire range from 0 to 255 and no adjustments will be made. This limitation is overcome by processing the full histogram of the image and doing some discrete calculus.
Images are processed and saved at their original resolutions. This can lead to some longer processing times on larger images but it's worth the wait!