Do Matlab functions imread and imwrite belong to image processing toolkit? its name seems like image processing functions, but if we look at here: http://www.mathworks.com/help/toolbox/images/ref/f3-23960.html they are not. Can anyone give some info?
Thanks alot.
No, IMREAD and IMWRITE are part of the core MATLAB toolbox.
Reading to or writing from 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:
>> 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