Simulink-Coder image data representation in C

Hello, I have a question related to an image representation out of Matlab Simulink Coder. If I have a Simulink block with an RGB image output size for instance 320x240x3, I get in my generated code an array with the size "img[230400]". My question is now, if I want to write this array to an .ppm-file-format, how do I have to iterate over this array to get a row based rgb order and see the image.

Thanks in advanced.

Answer 1

[Alain Kuchta]

Assuming img is an I x J x K array, the array element given in MATLAB by:

img(i,j,k)

can accessed in the generated C code at:

img[(k-1)*(J*I) + (j-1)*I + (i-1)];

For a more detailed explanation of how matrices and arrays are stored in generated code, refer to the following documentation:

http://www.mathworks.com/help/coder/ug/code-generation-of-matrices-and-arrays.html

[FJS]

Thank's, that helped. Column based thinking was the tricky part. Here is my solution:

     for(int i = 1; i <= dimy; i++)                                                   
         for(int j = 1; j <= dimx; j++)                                                
             for(int k = 1; k <= channel; k++)                                            
                fprintf(fp,"%d ",img[(k-1)*(dimx*dimy)+(j-1)*dimy+(i-1)]);