Reading a PPM image into a 2-dimensional array

**snorem** · 11-29-2014

Hi all, I'm trying to read a PPM image into an array. The header will have already been read in and I'm trying to put in a 2-d array to make manipulations easier. This is the code I have so far with LOTS of errors and warnings and I honestly don't know what almost any of them mean.

Code:

 
int imageArray( FILE *input, struct pixel *theArray ){
   int i, j;
   int col, row;


   int *imageArray = (int**)malloc(row * sizeof(int*));


   for(i=0; i<row; i++){
      imageArray[i]=(int*)malloc(col * sizeof(int));
      for(j=0; j<col; j++){
         fscanf(fpi, "%d", &imageArray[i][j];
      }
   }


   return 0;
}

**WoodSTokk** · 11-29-2014

On line 3 you declaring 'col' and 'row'.
On line 6 and 10 you use 'col' or 'row' for memory allocation, but you have never defined them.

And please, stop casting the returned value of malloc.

**snorem** · 11-29-2014

That should just give me random values then. It'll put whatever is stored in that spot into those integers. Those values will be read in from a different function that gets the header information and has absolutely nothing to do with what any of my errors are. My professor hasn't taught us anything about malloc so I don't really understand that either. I already corrected the error that came from not having a ')' on line 12. I have two warning about me initializing a pointer, the errors are that fpi is undeclared, I thought that was an fscanf thing I could just use like stderr? The errors are all on that line saying that the subscripted value is neither array nor pointer nor vector.

**Salem** · 11-30-2014

It's really hard to give you good advice when your code has so many errors, and then you bound back with "yeah, well I knew that part already".

> int *imageArray = (int**)malloc(row * sizeof(int*));
How about
a) this is the same name as your function
b) it should be an int** variable

> the errors are that fpi is undeclared
Perhaps because your input FILE* is called input.

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