Point operator C++

Question

I have the following piece of code for image processing, using the library CImg.

for (int y = 0; y < height; y++)
  for (int x = 0; x < width; x++) { 
      width = in.
      float weight = strength*x*(xmax-x)*y*(ymax-y)/(xmax*xmax)/(ymax*ymax);
      int new_x  = (int) ((1-weight)*x + weight*      y * xmax/ymax);
      int new_y  = (int) ((1-weight)*y + weight*(xmax-x)* ymax/xmax);
      out(x,y) = in(new_x,new_y);
  }

What does it mean the following line at the start of the cycle?

  width = in.

'width' and 'in' are respectively an int and a CImg object declared before.

Thank you.

@Niall there is no line like yours in the other part of the code. — charles, Sep 22 '14 at 14:21
@WouterHuysentruit The declaration of width is this: const int width = in.dimx(); but in the cycle the line is just that — charles, Sep 22 '14 at 14:23
@charles No, it won't compile. You're probably not running what you think you are. Either you're compiling another file or you didn't save the changes in the editor. — interjay, Sep 22 '14 at 14:26
@charles, be honest, you copied http://www.vision.ee.ethz.ch/~cvcourse/exercises/ex_0_materials/warp.cc and made a copy/paste mistake that doesn't compile — huysentruitw, Sep 22 '14 at 14:27

score 6 · Accepted Answer · answered Sep 22 '14 at 14:24

That line is a syntax error, and will not pass compilation. It most likely was accidentally pasted there.

Googling for the code gives this, which contains the same code without that line:

for (int y = 0; y < height; y++)
  for (int x = 0; x < width; x++) {
    float weight = strength*x*(xmax-x)*y*(ymax-y)/(xmax*xmax)/(ymax*ymax);
    int new_x  = (int) ((1-weight)*x + weight*      y * xmax/ymax);
    int new_y  = (int) ((1-weight)*y + weight*(xmax-x)* ymax/xmax);
    out(x,y) = in(new_x,new_y);
  }

Another part of the code contains the line const int width = in.dimx();, which is probably the source of the accidental copy/paste.

An answer doesn't always have to be complex to get upvotes. +1 from me ;) — huysentruitw, Sep 22 '14 at 14:29

Point operator C++

1 Answers1