**Name**

**ofdraw** Draw optical flow data

**Command Synopsis**

**ofdraw** [-a] [-m *m*] [-p *p*] [-z *z*] [-h *h*] *U* *V* *out*

-a : do NOT draw arrows

-mm: minimum norm threshold for drawing, default 0.

-pp: grid step for drawing, default 8, integer

-zz: zoom factor, default 2, integer

-hh: height of a unit speed vector in pixels, default 20

U: optical flow (input Fmovie of X coordinates)

V: optical flow (input Fmovie of Y coordinates)

out: output Cmovie

**Function Summary**

Cmovie ofdraw (U , V , a , m , p , z , h )

Fmovie U , V ;

float *m , *h ;

int *p , *z , *a ;

**Description**

This module takes optical flow data as input (that is, a 2D-vector
movie represented by 2 Fmovies *U* and *V*) and draw the 2D-vectors defined
on a discrete grid with step *p*. The output is a
Cmovie with a white background and vectors drawn in black as arrows.
Only lines may be drawn by specifying option `-a`

.
A zoom factor may be used with `-z`

option.
Vectors whose norm is below *m* are not drawn.
The output Cmovie may then be displayed with `cmview`

.

**Version 1.0**

Last Modification date : Thu Apr 15 05:50:59 2004

**Author**

Lionel Moisan