how to find the brightness of an image?
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how to find the brightness of a particular part of an image? and how to find the brightness of an entire image?
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Answers (2)
Walter Roberson
on 23 Sep 2012
If brightness is luminance, rgb2gray() the portion of the image.
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Image Analyst
on 23 Sep 2012
How do you define brightness? Is it just the mean? How about
brightness = mean2(yourImage);
or
brightness = mean2(yourImage(row1:row2, col1:col2));
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Shaun Roberts
on 11 Oct 2019
Hi Image Analyst,
Based on your Video Processing Tutorial - https://uk.mathworks.com/matlabcentral/fileexchange/47726-video-processing-tutorial?s_tid=prof_contriblnk
I am looking to expand the features so I can run an analysis of low level features to see if they can be used for video recommendation.
The first one I have been looking at is Brightness mean would it be possible to work this into your current example?
Image Analyst
on 12 Oct 2019
The program does compute the brightness of the gray scale version as well as each of the color channels. You can find this code in there:
% Calculate the mean gray level.
grayImage = rgb2gray(thisFrame);
meanGrayLevels(frame) = mean(grayImage(:));
% Calculate the mean R, G, and B levels.
meanRedLevels(frame) = mean(mean(thisFrame(:, :, 1)));
meanGreenLevels(frame) = mean(mean(thisFrame(:, :, 2)));
meanBlueLevels(frame) = mean(mean(thisFrame(:, :, 3)));
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