Performing Quantization on images

I have performed dwt2 on a image ,and have its coefficient,and sampled it,now i want to quantise the cA,cH coefficients to single image ,please help

the size of cA after sampling ,is 128x128 and cH after sampling is 128x128,now i want to perform quantization on cA,cH and get a single image please help

Answer 1

[Image Analyst]

I don't know what you mean. There is a new imquantize() in the Image Processing Toolbox - I think it started in R2012b. See if that will do what you want.

If you want to do stitching of images instead, just put the in brackets:

horizontallyStitchedImage = [image1, image2]
verticallyStitchedImage = [image1; image2]

Of course the dimension (number of rows or columns) along the stitching seam must be equal.

[FIR]

i am using 2010a,in my paper author had suggested to multiply DWT coefficients by a matrix for samplng,but i have multiplied by a single value.for sampling have we to multiply image by a matrix?please assist

[Image Analyst]

You'd do that by indexing, not by multiplication

subsampledMatrix = fullMatrix(1:2:end, 1:4:end); % or whatever...

[FIR]

in the link

http://imgur.com/gtsqU

XL,XH are wavelet coefficients,

phiL,phiH are sampled coefficients

from YL,YH i have to perform quantization and form single image

please help

[FIR]

I have to perform Compressive Sensing on cA,cH,please assist and have to perform CS recovery,please help

[Walter Roberson]

That's pretty far beyond the level of help that volunteers are usually willing to give. You should be working out the algorithms; we can help you with syntax and error messages.

[FIR]

ok walter can yo provide syntax for compressive sensing

[Image Analyst]

I think compressive sensing is way beyond FIR's abilities, and possibly beyond mine (though I've never delved into it). FIR, as you should know, Walter does not need to provide syntax because the syntax is already provided by the Mathworks in comprehensive help documentation, even including numerous examples in the help, and lots of training and tutorials (even video tutorials by Doug Hull) via MATLAB Central web site, as well as classroom instructor-led training. There is so much training on syntax that I'm surprised you haven't encountered it yet. But since you haven't I suggest you start with the Getting Started section of the help, and Doug Hull's video tutorials or the section on syntax here.

[Walter Roberson]

There is no special syntax for compressive sensing.

There are no Mathworks provided library routines or toolboxes specifically for compressive sensing. You can find some example code in the File Exchange.

http://www.mathworks.com/company/newsletters/articles/magic-reconstruction-compressed-sensing.html

http://www.mathworks.com/matlabcentral/fileexchange/28250-generate-figures-for-cleves-corner-on-compressed-sensing/content/Cleves_Corner_Compressed_Sensing.m