searchpattern
Drivers

Pattern finder. More...

Pattern finder.

The searchpattern driver searches for given patern in the camera image.

Compile-time dependencies

- none

Provides

- blobfinder
- (optionally) camera (thresholded image)

Requires

- camera

Configuration requests

- none

Configuration file options

- patterns (string array)
  - Default: Nothing! Explicit settings required.
  - Each string should contain one s-expression (a LISP-style list) which define one pattern; first element of a list is a 8-digit hex color value (0x prefixed): whenever given pattern is found it will be denoted by a blob of this color.
- debug (integer)
  - Default: 0
  - If it is set to non-zero, debug messages will be printed

Properties

- threshold (integer)
  - Default: 112
  - Valid values: 0..255
  - Luminance threshold used during thresholding see http://en.wikipedia.org/wiki/Thresholding_%28image_processing%29
- min_blob_pixels (integer)
  - Default: 16
  - Valid values: greater than 0
  - Minimal number of pixel for a blob to be considered as blob (used for noise elimination).
- sleep_nsec (integer)
  - Default: 10000
  - timespec value for additional nanosleep()

Example

    driver
    (
      name "searchpattern"
      provides ["blobfinder:0"]
      requires ["camera:0"]
      patterns ["(0x00ff0000 (black (white (black) (black (white)))))" "(0x0000ff00 (black (white) (white (black))))"]
      threshold 112
      min_blob_pixels 16
      debug 1
    )

Author
  Paul Osmialowski

Last updated 12 September 2005 21:38:45