Nios2 console output

Hello Everyone,

I am implementing edge detection using nios2. As an input , I have store my images as 128*128 array.
I have implemented sobel filter and as an output, I am expecting pixel values which i can read in matlab. My C program is working fine in any c compiler (like code blocks). When I am trying to run this c program on nios2, I am not getting any pixeles. If I try to run the same program using 15*15 or any small arrays, it is working and giving me output pixels.
Can anyone suggest me what should i do ?

Thanks