Why do I get an image in grey scale after imread the gif image?

My original image is with colour. I read the image file and display it, then I got a grey scale image. Does anyone know how I can load the image without change the colour scale? My code is like this: clear; close all;

I = imread('abc.gif')
figure, imshow(I);

Answer 1

[Image Analyst]

Don't name it I - that's a bad name - hard to tell the difference between I (upper case i), and l (lower case L), and 1. Plus it's not very descriptive.

Try this

[indexedImage, colorMap] = imread('abc.gif');
imshow(indexedImage);
colormap(colorMap);
colorbar;

[Anqi Li]

Thank you. It turns out in colour in the picture, but I don't understand why the colour (colour scale) changed. It looks very strange.

And I have the same problem when I imwrite the image after processing.

[Image Analyst]

The color should not change. Attach your images. Show your code where you read it in and display it and then call imwrite() and then read in the saved image and display it where it demonstrates that the colors changed.

[Anqi Li]

Here is my code and my result. My purpose is to segment and calculate the length of the edge.

[Anqi Li]

[Image Analyst]

You forgot to apply the colormap to the image you read back in. So you're seeing the indexes as a grayscale image, which is pretty much nonsense/gibberish.

[Anqi Li]

But how about the colour changing ?

[Image Analyst]

You have it displayed 3 times. Each figure is using a different colormap.

[Image Analyst]

Do you still not understand and need more explanation?