I have tried with tif images and it works. Maybe your error it is due to the matlab version, which version do you use?
Remember that to run the application it is necessary to type "img_lab" into the command line ;)
When i run the gui, and i choose a photo(.tif) i took a message saying: Index exceeds matrix dimensions.
Error in ==> show_rgb at 16
Is there any idea how to get rid of that problem?
Thank you in advance :)