title: Converting an RGB image to grayscale and manipulating the pixel data in python
body: <p>I have an RGB image which I want to convert to a grayscale image, so that I can have one number (maybe between 0 and 1) for each pixel. This gives me a matrix which has the dimensions equal to that of the pixels of the image. Then I want to do some manipulations on this matrix and generate a new grayscale image from this manipulated matrix. How can I do this?</p>