image processing

Probably refers to the size of the kernel used to convolve an image. Think of replacing every pixel (target) in an image with some kind of aggregate measure of itself and the pixels around it (source). You're applying a local average (or similar function) at every pixel. The filter size refers to how many source pixels around the target pixel go into the calculation.

Usually it's a size of the area where samples would be taken from image. For example 3x3 tap would look like that (in terms of texture coords):
[-1,-1][ 0,-1][ 1,-1]
[-1, 0][ 0, 0][ 1, 0]
[-1, 1][ 0, 1][ 1, 1]

ok so if i say size of gabor filters is 11, does that mean that it will be a matrix of size 11x11.ie 11 neighbouring pixels??

I guess it would be 121, amount of pixel in square of 11 by 11 pixels.

ie a matrix of size 11 x 11??

ok, can u please help me with some information on how filtering is done on an image..

what i understand is that a matrix of the size is placed on a pixel(i,j) and the gray value is calculated..is it??

pls suggest some good tutorials/books??

Depends on your goals, you want to do it in realtime or that would be offline application, kind of a filters in Photoshop?

Calucalting grey or other values depends on filter algoritm, but in general you make a loop where you would read sample from texture, one by one, and do your math on them. For example simple box filter would read 3x3 samples from texture, sum them and divide by 9. Sampling is made by calculating proper texture coordinates. You dont need matrix for this, it can be a simple array:
[-1,-1]
[ 0,-1]
[ 1,-1]
[-1, 0]
[ 0, 0]
[ 1, 0]
[-1, 1]
[ 0, 1]
[ 1, 1]

thanks for your reply..

i want to use filter on an image to remove the noise..say as in fingerpint image..

so how does filter work on it? particularly Gabor filter?

no reply yet

plssss

A quick google search returned this:
http://mplab.ucsd.edu/tutorials/pdfs/gabor.pdf

If you aren't familiar with impulse response functions and are new in general to image processing, you might want to read up some signal processing fundamentals first. A very good resource is 'Principles Computerized Tomographic imaging' by Kak and Slaney. The book is available as separate chapters in PDF here:

http://www.slaney.org/pct/

The first couple of chapters might be very helpful.