Multiplying matrix to an greyscale image

Hi guys! Nowadays I'm interested in image processing, and now studying about image transformation. So, I want to use some transforming matrix, such as rotating or enlarging.

So, I want to make write a function that multiply a given matrix to an image. I KNOW THERE IS A FUNCTION TO DO THAT but I just want to write a new one, without using other functions.

I think moving each pixels to new location is not a big deal, but I want to know how I can add interpolation features, like bilinear or nearest point. Especially the corner of image where I can use only one point to determine the greyscale of empty pixels. Thanks!

[DGM]

You can always open the existing tools and see what you can find out.

open imtransform
open tformarray

There may also be other private functions in the directories beneath matlabroot/toolbox/images/images/

Answer 1

[Image Analyst]

See Steve's blog:

Spatial transformations Defining and applying custom transforms Steve on Image Processing