resizing an image not working.
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Hello, I am trying to resize a color image by using alternate pixel values. What I am getting is a blue image with a few black dots.I changed it to gray but now I am getting a white image with black image with a few black dots. Can someone tell me how to do the color resize, what is wrong with my script please
Thank you
%read image
a =imread('beach.jpg');
a= rgb2gray(a);
[rows,columns] = size(a);
i = 1, j =1;
c=zeros(rows/2,columns/2);
for x = 1:2:rows
for y = 1:2:columns
c(i,j) = a(x,y);
j = j + 1;
end
i = i +1;
j = 1;
end
imshow(c);2 个评论
madhan ravi
2018-10-21
编辑：madhan ravi
2018-10-21
upload your .jpg file to test , you didn't attach the file
Image Analyst
2018-10-21
采纳的回答
For a greyscale image, your code is correct (as long as the size of the image is even) although note that iterating over rows in the inner loop and columns in the outer one would be faster due to the way matlab stores matrices in memory.
For colour image, your code will only look at the red channel, since it works on 2D arrays whereas colour images are 3D.
Of course, the whole thing is a waste of time, the following one liner would do the same more simply:
resizedimage = originalimage(1:2:end, 1:2:end, :);
with the added bonus that it works both for colour and greyscale images and works for odd and even sized images.
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