Find max value on images

How to find the max value of those punch of images

Answer 1

[Image Analyst]

What is a "punch" of images? And what is your definition of brightest for a color image? Do you just want to convert to gray scale and find the brightest? Something like (untested)

grayImage = rgb2gray(rgbImage);
maxValue = max(grayImage(:))
maxMap = grayImage == maxValue;
rgb2 = imoverlay(grayImage, maxMap);
imshow(rgb2);

[Mohamed Elbeialy]

Just need to find the max value on each image, then imshow the result

[Image Analyst]

OK, then you're all set. Did you try it?

[Mohamed Elbeialy]

I tried it and it marked the top of the image in some case and did not show any differencce in other cases. Is that the correct max value on an image. How about if I want to adjust the max value to specific number like 3?

[Walter Roberson]

rgbImage = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/591002/image.jpeg');
grayImage = rgb2gray(rgbImage);
maxValue = max(grayImage(:))

maxValue = uint8 255

maxMap = grayImage == maxValue;
R = grayImage;
G = grayImage;
B = grayImage;
R(maxMap) = 255;
G(maxMap) = 0;
B(maxMap) = 0;
rgb2 = cat(3,R,G,B);
image(rgb2); 

nnz(maxMap)

ans = 34

[r,c] = find(maxMap);
[r(1), c(1)]

ans = 1×2

328 39

figure
image(rgb2); hold on
scatter(c, r, 'b*')
hold off

[Mohamed Elbeialy]

Why should it be converted to grayimage, could I use it as colored ?

[Walter Roberson]

rgbImage = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/591002/image.jpeg');
grayImage = rgb2gray(rgbImage);
maxValue = max(grayImage(:))

maxValue = uint8 255

maxMap = grayImage == maxValue;
R = rgbImage(:,:,1);
G = rgbImage(:,:,2);
B = rgbImage(:,:,3);
R(maxMap) = 255;
G(maxMap) = 0;
B(maxMap) = 0;
rgb2 = cat(3,R,G,B);
image(rgb2); 

nnz(maxMap)

ans = 34

[r,c] = find(maxMap);
[r(1), c(1)]

ans = 1×2

328 39

figure
image(rgb2); hold on
scatter(c, r, 'b*')
hold off

[Mohamed Elbeialy]

How to apply the code to number of images then save the new images in a new folder .

Also, remove the image scale

[Image Analyst]

If you use imoverlay, and the max occurs only at a few isolated pixels, then it won't be very visible will it? You can put hold on and use a marker like s cross or spot to make it more visibile. Control the size of the spot with the 'MarkerSize' option

hold on
plot(c, r, 'r.', 'MarkerSize', 15); % Or whatever size you want.

[Mohamed Elbeialy]

How to classify images depending on the shape of each image's object

[Walter Roberson]

Classification by shape is a totally different topic. You asked that question in https://www.mathworks.com/matlabcentral/answers/808630-how-to-classify-images-depending-on-the-shape-of-each-image-s-object?s_tid=prof_contriblnk

[Image Analyst]

@Mohamed Elbeialy, I'll take a look at that when/if I get time. But did this answer solve this problem? If so, please accept it.