MATLAB: batch processing of images and, saves these images. How can I do?

Question

I'm sorry, I'm a newby. I tried to copy the code find here to obtain the same result, but it doesn't work (fault mine). I can not figure out how saveas can understand which is the image that has to save. I've read that saveas wants a Handle and a filename as input, and in the code that I fund in the link above I don't see these arguments:

saveas(sprintf('img%d.tif',num_picture))

Here is a short part of my code:

% Here a loop that transform aeach image inside the variable(cell array) 'immages'

for z = 1:length(immages) %images is a cell array contained the matrices of 100images
    temp = immages{z};  %temp means temporary, that is the image to process
    for i = 1:I       % begin of cycle that process each pixel of the image(tmp)
        for j = 1:J
            if temp(i,j) == 0
               temp(i,j) = 115;
            else
                temp(i,j) = 140;
            end
        end
    end
    cd(finalDest);  %move into the directory whre I want to save the new image
    figure;
    imshow(temp);
    saveas(sprintf('img%d.tif',z)); % HOW CAN I SAVE THE CURRENT IMAGE(TEMP) INSIDE 'FINALDEST'?
    cd(initialDest); %return to the folder where the original images are contained
end

I encounter this error ERROR USING SAVEAS, line55: Requires handle to Figure or block diagram and filename.

Thank you so much.

Answer 1

You are right, saveas needs a figure handle as first parameter, you can get one changing:

figure;

with

h = figure(z); //one figure per image

and

saveas(h, sprintf('img%d.tif',z));

or using gcf to get a handle to the current figure:

saveas(gcf, sprintf('img%d.tif',z));

If you only want to save the information on the temp matrix (not the entire figure) you should use IMWRITE :

imwrite(temp,sprintf('img%d.tif',z));