CODEWITHSUNDEEP
imagematlab
Jason
Jason

Reputation: 1613

read image but show strange colour

I have read a image like that

a = imread('test.jpg');
image(a)

what the test.jpg is:

Original image

but after the image function

the result is:

Obtained image

and I don't know why it show that?

Because I want to crop some part, so I have to see the image shown.

How to fix it by showing the human face by image?

Upvotes: 0

Views: 49

Answers (2)

Diederick C. Niehorster
Diederick C. Niehorster

Reputation: 973

You image data might be in a color map instead. try [a,cmap] = imread(...). If cmap is not empty, a is indices into cmap, and cmap contains the actual colors. Use img = cat(3,cmap(a,1),cmap(a,2),cmap(a,3)) to get your image, and show it with image(img).

Note that using imagesc might be misleading in this case as it will still show something that looks like your image when simply doing imagesc(a). This as different pixels colors are associated with different index-values in a.

Upvotes: 0

Autonomous
Autonomous

Reputation: 9075

You are using image command to display an image. From here: "image creates an image graphics object by interpreting each element in a matrix as an index into the figure's colormap or directly as RGB values". Since you are providing a 2-D matrix, each element is interpreted as the index to the figures colormap. You can see the figure's colormap by using 

 c_map=colormap;

Also, the axis is set to square, therefore you see a circle instead of an ellipse. Use imshow(a,[]) to display the grayscale image as desired.

Upvotes: 1

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