convertion of rgb 2 gray from the gray image, how to retrieve the original image

Hi all, I want to convert to a RGB image into grayscale image.and i want to get back the original image. How should I get back the original image from the grayscale image. For example, A=imread('bird.png'); B=rgb2gray(A);

Now i want to get back the the image A from B.

[Image Analyst]

Your duplicate question is in http://www.mathworks.com/matlabcentral/answers/86854-how-to-convert-a-gray-scale-image-to-color-image-using-matlab - don't forget to look at the answers there. By the way, why did you want answers to be split across two different, yet identical, postings?

Answer 1

[Walter Roberson]

You cannot do that if all you have is the grayscale image. If you are using 8 bits per channel for your images, then there are 65536 different color combinations that match any one grayscale level, so you do not know which of the 65536 possibilities to map any given grayscale level back into.