imread_irfanview(fi​lename)

Matlab sometimes does not support an certain image format. For instance Error reading bmp data Bitfield compression not supported.
This function imread_irfanview, uses the installed Irfanview application to convert the not-supported image file to a TIF file supported by Matlab.
Note, probably you have to change the PATH to the Irfanview application inside your code.
Example,
I = imread_irfanview('test.bmp');
figure, imshow(I);