MATLAB: Grayscale image and imshow

image processionwindow function

I have a grayscale jpg image. I have used a window function to bring the edges down to 0 however over the range that i have multiplied (coulombs and rows on the outer edges of the image) by the window function there is a light blue tint in the picture ???
imshow should only display in black and white should it not??

Best Answer

If you have a "grayscale jpg image" then that could mean that you started with an RGB image in which the R, G, and B channels were all equal. Manipulating such an image could potentially end up with unequal channels.
The alternative is that you had an indexed (pseudocolor) image whose colormap consisted entirely of gray entries; if so then the color the image would show up would depend upon the colors available in the colormap you are using.
Please check the size() of the image: it would have 3 dimensions if it is a truecolor image whose R, G, and B were all equal.
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