sketch recognition

I AM USING THIS PROGRAM FOR SKETCH RECOGNITION HOWEVER IT IS GIVING ME THE ERROR ??? Subscripted assignment dimension mismatch.

Error in ==> sym_rec_main2 at 60 I3Dtotal(:,:,2) = Ibw3D2;

WHAT AM I DOING WRONG?

I3D1 = imread('IMG_0001.jpg');
I3D2 = imread('IMG_0002.jpg');
I3D3 = imread('IMG_0003.jpg');
I3D4 = imread('IMG_0004.jpg');

size3Dr = input('Enter number of training sets');
size3Dc = input('Enter number of different symbols');
sizer = size3Dr; %Assuming equal traning sets
sizec = size3Dc;

noimages = sizer/6;

Igray1 = rgb2gray(I3D1);
Ibw3D1 = im2bw(Igray1,graythresh(Igray1));
Igray2 = rgb2gray(I3D2);
Ibw3D2 = im2bw(Igray2,graythresh(Igray2));
Igray3 = rgb2gray(I3D3);
Ibw3D3 = im2bw(Igray3,graythresh(Igray3));
Igray4 = rgb2gray(I3D4);
Ibw3D4 = im2bw(Igray3,graythresh(Igray4));
I3Dtotal(:,:,1) = Ibw3D1;
I3Dtotal(:,:,2) = Ibw3D2;
I3Dtotal(:,:,3) = Ibw3D3;
I4Dtotal(:,:,3) = Ibw3D4;

rfactor = 1; crpval = 0;

for i = 1 : noimages

    I = I3Dtotal(:,:,i);
    img = sym_rec_img_preprocess(I, size3Dr, size3Dc, noimages);
    for cnt = 1:((size3Dr*size3Dc)/noimages)
        bw2 = img_crop(img{cnt}, rfactor, crpval);
        charvec = img_resize(not(bw2));
        out3D(:,cnt,i) = charvec;
    end

end

Answer 1

[Walter Roberson]

Use size() to check that all of the I3D* image arrays are the same size.

[stephanie borg]

NO THEY'RE NOT EXACTLY EQUAL BUT CLOSE. COULD THAT BE THE ERROR? HOW CAN I ARRANGE THEM TO BE THE SAME?

[Walter Roberson]

You can prevent the error by using code like this:

maxdims = max([size(Ibw3D1); size(Ibw3D2); size(Ibw3D3); size(Ibw3D4)]);

I3Dtotal = zeros([maxdims(1), maxdims(2), 4], class(Ibw3D4));

I3Dtotal(1:size(Ibw3D1,1),1:size(Ibw3D1,2),1) = Ibw3D1;

I3Dtotal(1:size(Ibw3D2,1),1:size(Ibw3D2,2),1) = Ibw3D2;

I3Dtotal(1:size(Ibw3D3,1),1:size(Ibw3D3,2),1) = Ibw3D3;

I3Dtotal(1:size(Ibw3D4,1),1:size(Ibw3D4,2),1) = Ibw3D4;

This will use zeros in the locations where the arrays were smaller.

Alternately, you could use,

mindims = min([size(Ibw3D1); size(Ibw3D2); size(Ibw3D3); size(Ibw3D4)]);

and then you could

Ibw3D1 = imresize(Ibw3D1,mindims);

Ibw3D2 = imresize(Ibw3D2,mindims);

and so on, after which you could use your existing Ibwtotal code. This would not use zero padding anywhere, but would have the disadvantage of interpolating some of the arrays to fit the smallest size which will introduce artifacts. (You could resize to maxdims instead of mindims if you wanted.)

[stephanie borg]

CAN I PLEASE TALK TO YOU ON YOUR PERSONAL EMAIL? THANKS

[Walter Roberson]

It is 07:00 here and I am going to bed in a moment. It is better to post your questions as others may be able to answer them. Especially if they are questions about the sketch recognition portion, as I am not familiar with the techniques used for sketch recognition.

[stephanie borg]

ok i understand. because this program is supposed to work. im afraid i have something wrong in the sketches but i dont know.

Answer 2

[Tim Zaman]

The images you are using in this code have to be the exact amount of pixels: so if image 1 is 800x600, image 2 has to be 800x600 too. Common error with image processing.

[stephanie borg]

you're right! they're not the same.. do you know from where i can change that? thanks

[Walter Roberson]

You could use the imresize() suggestion I made earlier. You will have to decide whether you want to size the small images up, or the larger images down.