searchpattern

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