How to write the code for the average luminance of input image?

I'm having a trouble for coding the average luminance of the image. This the formula for that

Yaveg =Yi,j (1) where Yi,j = 0.3R + 0.6G + 0.1B, Yi,j is normalized to the range (0,255), and i, j are the index of pixel.

Please help this is for my thesis, its my first time to use matlab :(

Answer 1

[Image Analyst]

Why not use

grayImage = rgb2gray(rgbImage);
meanGrayLevel = mean2(grayImage);

That's how most people would do it. If you have special coefficients you want to use for some reason then you can do

% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
% Combine separate color channels into weighted average to get the gray scale image.
grayImage = 0.3 * redChannel + 0.6 * greenChannel + 0.1 * blueChannel;
meanGrayLevel = mean2(grayImage);

[Jayzel Castro]

Thank you so much! I will try this code :) thanks again :)