1. Point operations modify pixel values without changing the image size or structure. Each new pixel value depends only on the original value at that point. 2. Histogram equalization finds a point operation to make the modified image histogram approximate a uniform distribution. This can only shift and merge histogram entries, not split them. 3. Other point operations discussed include increasing brightness by adding a constant value to each pixel, inverting pixels by subtracting from 255, thresholding to make pixels above a level white and below black, and alpha blending images with transparency control. 4. Automatic contrast adjustment and increasing contrast by multiplying pixel values by 1.5 are also point operations described.

1. Point Operations in Image ProcessingR.Logarajah(2005/SP/30)Department of Computer Science, University of JaffnaHistogram EqualizationBrightnessIntroductionPoint operation perform a modification of the pixel values without changing the size, geometry, or local structure of the image. Each new pixel value a′=I′(x,y) depends exclusively on previous value a=I(x,y) at the same position and is independent from any other pixel value in particular from any of its neighboring pixels.