How to find energy of image ?
조회 수: 35 (최근 30일)
이전 댓글 표시
Hello, i have to find energy of an image in matlab. I want to compare energy of decomoposition levels in DWT. I am looking for number of this energy.
Thank you
댓글 수: 0
답변 (2개)
Subhadeep Koley
2020년 3월 1일
If you want to calculate "Energy" as defined from the gray level co-occurrence matrix of the image then the following code might help.
% Read the image
img = imread('cameraman.tif');
% Create gray-level co-occurrence matrix from image
glcms = graycomatrix(img);
% Calculate properties of gray-level co-occurrence matrix
stats = graycoprops(glcms);
% Display energy values
disp(['Energy = ', num2str(stats.Energy)]);
댓글 수: 0
Image Analyst
2020년 3월 1일
Light falls onto a sensor with units of watts per square meter, and a pixel has an area of square meters, and the illumination is collected for some number of seconds, so you can see that the signal (gray level) is a unit of energy. Just do the math on the units. Since a watt is a joule per second:
[joules/(sec * m^2)] * m^2 * sec = joules.
So one definition of energy could be to simply sum up all the gray levels
energy = sum(grayImage(:));
Of course that's a proportionality - the value is not the number of joules directly.
댓글 수: 0
참고 항목
카테고리
Help Center 및 File Exchange에서 Discrete Multiresolution Analysis에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!