Question

Do the MATLAB functions imread and imwrite belong to the image processing toolkit? The names seem to suggest that they do, but I’m not sure. Can anyone give some info?

Answer 1

No, imread and imwrite are part of the core MATLAB toolbox.

Reading from or writing to image files is a basic IO process, and one that many people will likely have need to do without any need for processing the images. For example, if you just want to display an image in a figure, you shouldn’t need a whole new high-powered image processing toolbox just to do that. That’s why there are simple functions like image and imagesc present in the core MATLAB toolbox, while the Image Processing Toolbox has an additional imshow function that has a few more bells and whistles.

In general, you’ll find that a lot of basic/common operations are present in the core MATLAB toolbox, while the more advanced operations require a specialized toolbox. The names of the functions themselves won’t really tell you which toolbox they belong to, but you can use the which function if you are ever in doubt about where a function lives. For example, for MATLAB R2009a:

>> which imread
C:\Program Files\MATLAB\R2009a\toolbox\matlab\imagesci\imread.m
                                     % ^---- Core MATLAB toolbox
>> which imshow
C:\Program Files\MATLAB\R2009a\toolbox\images\imuitools\imshow.m
                                     % ^---- Image Processing Toolbox