facedetect
Performs face detection on videos and images. If you have high cpu load you need to use videoscale with capsfilter and reduce the video resolution.
The image is scaled down multiple times using the GstFaceDetect::scale-factor until the size is <= GstFaceDetect::min-size-width or GstFaceDetect::min-size-height.
Example launch line
gst-launch-1.0 autovideosrc ! decodebin ! colorspace ! facedetect ! videoconvert ! xvimagesink
Detect and show faces
gst-launch-1.0 autovideosrc ! video/x-raw,width=320,height=240 ! videoconvert ! facedetect min-size-width=60 min-size-height=60 ! colorspace ! xvimagesink
Detect large faces on a smaller image
Hierarchy
GObject ╰──GInitiallyUnowned ╰──GstObject ╰──GstElement ╰──GstBaseTransform ╰──GstVideoFilter ╰──GstOpencvVideoFilter ╰──facedetect
Factory details
Authors: – Michael Sheldon
Classification: – Filter/Effect/Video
Rank – none
Plugin – opencv
Package – GStreamer Bad Plug-ins
Pad Templates
sink
video/x-raw:
format: RGB
width: [ 1, 2147483647 ]
height: [ 1, 2147483647 ]
framerate: [ 0/1, 2147483647/1 ]
src
video/x-raw:
format: RGB
width: [ 1, 2147483647 ]
height: [ 1, 2147483647 ]
framerate: [ 0/1, 2147483647/1 ]
Properties
display
“display” gboolean
Sets whether the detected faces should be highlighted in the output
Flags : Read / Write
Default value : true
eyes-profile
“eyes-profile” gchararray
Location of Haar cascade file to use for eye-pair detection
Flags : Read / Write
Default value : /usr/share/opencv4/haarcascades/haarcascade_mcs_eyepair_small.xml
flags
“flags” Opencv-face-detect-flags *
Flags to cvHaarDetectObjects
Flags : Read / Write
Default value : do-canny-pruning
min-neighbors
“min-neighbors” gint
Minimum number (minus 1) of neighbor rectangles that makes up an object
Flags : Read / Write
Default value : 3
min-size-height
“min-size-height” gint
Minimum area height to be recognized as a face
Flags : Read / Write
Default value : 30
min-size-width
“min-size-width” gint
Minimum area width to be recognized as a face
Flags : Read / Write
Default value : 30
min-stddev
“min-stddev” gint
Minimum image average standard deviation: on images with standard deviation lesser than this value facedetection will not be performed. Setting this property help to save cpu and reduce false positives not performing face detection on images with little changes
Flags : Read / Write
Default value : 0
mouth-profile
“mouth-profile” gchararray
Location of Haar cascade file to use for mouth detection
Flags : Read / Write
Default value : /usr/share/opencv4/haarcascades/haarcascade_mcs_mouth.xml
nose-profile
“nose-profile” gchararray
Location of Haar cascade file to use for nose detection
Flags : Read / Write
Default value : /usr/share/opencv4/haarcascades/haarcascade_mcs_nose.xml
profile
“profile” gchararray
Location of Haar cascade file to use for face detection
Flags : Read / Write
Default value : /usr/share/opencv4/haarcascades/haarcascade_frontalface_default.xml
scale-factor
“scale-factor” gdouble
Factor by which the frame is scaled after each object scan
Flags : Read / Write
Default value : 1.25
updates
“updates” Face-detect-updates *
When send update bus messages, if at all
Flags : Read / Write
Default value : every_frame (0)
Named constants
Face-detect-updates
Bus messages update scheme
Members
every_frame (0) – Send update messages on every frame
on_change (1) – Send messages when a new face is detected or one is not anymore detected
on_face (2) – Send messages whenever a face is detected
none (3) – Send no messages update
Opencv-face-detect-flags
Flags parameter to OpenCV's cvHaarDetectObjects function.
Members
do-canny-pruning (0x00000001) – Do Canny edge detection to discard some regions
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