Apply the Equalize filter, Using the Equalize command (Photoshop) The Equalize command redistributes the brightness values of the pixels in an image so that they more evenly represent the entire range of brightness levels. When you apply this command, Photoshop finds the brightest and darkest values in the composite image and remaps them so that the brightest value represents white and the darkest value represents black.
The Brightness/Contrast adjustment lets you make simple adjustments to the tonal range of an image. Moving the brightness slider to the right increases tonal values and expands image highlights, to the left decreases values and expands shadows. The contrast slider expands or shrinks the overall range of tonal values in the image.
When you apply the Equalize adjustment, Photoshop finds the lightest areas in your image and makes them white. At the same time it locates the darkest image areas and forces them to black.
