Working with tiff's in matlab

Question

How do find out what bit a file is? I have a tiff and convert it to class double to work with the values in the command line. When I do that though the histogram (256 bins) looks like it is binary when that isn't the case for the original file. Why is that? How do I correct that? Another odd thing is the image that I get isnt binary, you can actually see different shades of gray.

Answer 1

Im not sure I understood the problem but to get a detailed information of an image file, use the IMFINFO function

Answer 2

I assume that you converted the image to double using IM2DOUBLE. This rescales the image so that its values are distributed between 0 and 1 (for example, the pixel values of an 8-bit image would be divided by 255).

If you were to plot the histogram with hist(img(:),(0:255)/255), where img is the converted image, you'd see the 256 bins as you'd expect them.