How I can generate an image and modify it with Matlab?
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Hello,
Is it possible to generate an image with defined row and column numbers without going through the generation of a 2D matrix.
Usually, I created the image according to the following code :
A=3000*ones(200,200);
imwrite(A,['image' num2str(1) '.jp2']);
I want generate an image with 200 rows and 200 columns without generate the matrix A.
My second question, how can I modify an element (the value of a pixel) of an image?
Thank you!
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Accepted Answer
Kanika Gupta
on 24 Jun 2020
Edited: Kanika Gupta
on 24 Jun 2020
Try using this to create a blank image of desired size
blankimage=zeros(200,200)
imshow(blankimage)
To change value at specific location simply do
blankimage(1,1)=255
2 Comments
Kanika Gupta
on 24 Jun 2020
The maximum size of array supported by Matlab is 10,000. This can be seen
home > preferences > workspace > maximum array size.
If you wish to use it for larger arrays, refer to https://www.mathworks.com/help/matlab/matlab_prog/resolving-out-of-memory-errors.html
More Answers (1)
Image Analyst
on 24 Jun 2020
Use the uint16 option in ones to cut down the size by a factor of 4. If you use ones() without it, you're using floating point values and have 8 bytes instead of 2 bytes and uint16.
A = 3000 * ones(200, 200, 'uint16');
imwrite(A, 'image1.jp2');
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