please help : Subscripted assignment dimension mismatch. Error in dct (line 13) imred(:,:,1) = uint8(red);

function dct(I) coder.extrinsic('dctmtx');

%dctmtx - Compute discrete cosine transform matrix. T = dctmtx(8); red = double(I(:,:,1)); coder.extrinsic('imred'); imred = zeros(8,8);

        imred(:,:,1) = uint8(red);

B = blkproc(imred,[8 8],'410*x*500',T,T'); mask = [16 11 10 16 24 40 51 61; 12 12 14 19 26 58 60 55; 14 13 16 24 40 57 69 56; 14 17 22 29 51 87 80 62; 18 22 37 56 68 109 103 77; 24 35 55 64 81 104 113 92; 49 64 78 87 103 121 120 101; 72 92 95 98 112 100 103 99]; B2 = blkproc(B,[8 8],'410.*x',mask); I2 = blkproc(B2,[8 8],'410*x*500',T',T);

[Rik]

Have a read here and here.

Right now I can't really see what is going on and what is exactly your question.

[jebli med]

    this is  my code i use  hdl coder  in
 matlab to  convert my code  but i have 
this error :"Subscripted assignment dimension
 mismatch. Error in dct (line 13) imred(:,:,1) = uint8(red);"

please can you help me

function dct(I)

coder.extrinsic('dctmtx'); 
%dctmtx - Compute discrete cosine transform matrix.
T = dctmtx(8);
red = zeros(8,8,1);
 red = double(I(:,:,1));
coder.extrinsic('imred');
coder.extrinsic('blkproc');

   imred(:,:,1) = uint8(red);

B = blkproc(imred,[8 8],'410*x*500',T,T');
mask = [16 11 10 16 24  40  51  61;
        12 12 14 19 26  58  60  55;
        14 13 16 24 40  57  69  56;
        14 17 22 29 51  87  80  62;
        18 22 37 56 68  109 103 77;
        24 35 55 64 81  104 113 92;
        49 64 78 87 103 121 120 101;
        72 92 95 98 112 100 103 99];

B2 = blkproc(B,[8 8],'410.*x',mask);
I2 = blkproc(B2,[8 8],'410*x*500',T',T);

   %figure, imshow(I4);
   image(:,:,1)=I2;
   image(:,:,2)=I3;
   image(:,:,3)=I4;

       figure,
           subplot(1,2,1); imshow(I); title('image originale')
           subplot(1,2,2); imshow(image); title('image compressée')       

           end