How do I Cut the black edge of the image automatically

As title, how do I make the edge cutting by masking automatically(about 300 pictures)?

I make one edge cutting as the example

thanks!

Answer 1

[DGM]

This is one way to automatically crop off nominally-solid color borders.

% read the image, create a grayscale copy
inpict = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1236847/raw_picture.jpg');
testpict = im2double(rgb2gray(inpict));

% find the central region by looking at the
% variance along row/column vectors
% nonzero threshold allows for noise in BG
th = 0.005;
varx = var(testpict,0,1)>th;
vary = var(testpict,0,2)>th;

% extract the central region
xrange = find(varx,1,'first'):find(varx,1,'last');
yrange = find(vary,1,'first'):find(vary,1,'last');
outpict = inpict(yrange,xrange,:);

imshow(outpict)

For processing multiple images, there are a number of examples around. This is a good starting point.

https://www.mathworks.com/matlabcentral/answers/57446-faq-how-can-i-process-a-sequence-of-files

https://www.mathworks.com/matlabcentral/answers/62399-how-to-load-multiple-images-and-processing-them

[Bill Chen]

thanks a lot! It works! Could I input a fold and output with a stored fold?

[Bill Chen]

Oh! I will take a look at your example first, thanks!

Answer 2

[Image Analyst]

To process a sequence of files, see code snippets in the FAQ:

https://matlab.fandom.com/wiki/FAQ#How_can_I_process_a_sequence_of_files?