Matlab GUI图像不正确的蓝色

Question

I am creating a GUI containing an image using the following code:

try
    Imagenamehere = imread('Imagenamehere.jpg');
    axes(handles.Logo)
    image(Imagenamehere)
    set(gca,'xtick',[],'ytick',[])
catch
    msgbox('Please download all contents from the zipped file into working directory.')
end

The image shows up but for some reason is completely coloured blue as if put through a blue filter. I don't think it would be wise to upload the image but it is a simple logo coloured black and white.

Anyone know what could be causing this?

Answer 1

Check the size, type (probably uint8 ) and range of your image. It sounds like for some reason your images are being displayed with colormap as jet (the default), and possibly also that your range is not what MATLAB expects (eg 0 to 1 not 0 to 255), resulting in all your values being relatively low (blue on the jet colormap).

"black and white" is just one way of interpreting an image file which contains only two colors. MATLAB makes several assumptions when you pass data into a display function like image . If you don't specify colormap and image data range, it will make a guess based off things like data type.

One possibility is that your logo file is an indexed image. In these cases you need to do:

[Imagenamehere map] = imread('Imagenamehere.jpg');
colormap(map);