image processing

how to read 100 images at a time ? what will appear on the output? how to analyzed the output?

[Jan]

Please post any details. It is not clear what "appear on the output" could mean. And there are thounds of methods to "analyse" a set of pictures.

[ganesh s]

how to analysed the data base containing 100 images or how to compare the 100 images which has to be read through single program on the basis of standard deviation & mean ?????

[Jan]

@Ganesh: Please post the necessary details. Did you install Matlab already, do you have the Signal-Processing-Toolbox, are you able to read each single file, if so, how and in which format are they written to memory? Do they have the same dimensions? What does "analyse base on mean and std" mean exactly? The mean over the pictures, or the std over the mean of each image?

This forum is very efficient for finding answers, but we cannot guess, what the question is.

[ganesh s]

@ jan simon :sir i have installed matlab already.with signal processing tool box in it & i know how to read & show the single image at a time (using imread & imshow function ). all the images in the data base are of same size(dimension) and of .jpg format

i am first converting the color image in to gray (using rgb2gary ) then finding it's FFT & then i need to take the first & second movements of the output image obtain from the FFT ( ie mean & std to extract the feature of the image )

i know how to find it for the single image . but i don't know how to find it for data base of the image which contain 100 images using single program .i know using for loop we can do this but i don't know how to analyzed the output base on the coefficient of the images(obtain in the matlab array editor ) & what will be expected output

[Jan]

@Ganesh: Thanks, now the question is much easier to understand.

[ganesh s]

@ jan simon : thanks sir for guiding me

Answer 1

[Sean]

Ganesh,

If you are trying to observe the change in each parameter over time (i.e. from image 1 to image 100), just use a for loop around the load/calculate/release for each image and dump the desired parameters into an output array. for example:

    for imagecount=1:100
    (code:load/calculate/release image)
    output(:,i)=[mean stdev];
    end

You can then plot or otherwise analyze the trends in mean/stdev.

If you want to get the mean/stdev of the whole datacube, then use a for loop the genereate the entire cube.

    for imagecount=1:100
    (code: load image & convert to grey)
    datacube(:,:,imagecount)=<imagematrix>
    end
    mu=mean(datacube(:))
    sigma=std(datacube(:))

[ganesh s]

thanks sir it will solve my problem.

Answer 2

[Walter Roberson]

Please see http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

[ganesh s]

@ walter Roberson : thanks sir for providing me this link it will very helpful to me