ALColorBlobDetection API

NAOqi Vision - Overview | API

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Namespace : AL

#include <alproxies/alcolorblobdetectionproxy.h>

Method list

class ALColorBlobDetectionProxy

• As any module, this module inherits methods from ALModule API.
• It also inherits methods from ALExtractor API.
  • ALColorBlobDetectionProxy::setColor
  • ALColorBlobDetectionProxy::setObjectProperties
  • ALColorBlobDetectionProxy::getCircle
  • ALColorBlobDetectionProxy::getAutoExposure
  • ALColorBlobDetectionProxy::setAutoExposure

Event list

• ALTracker/ColorBlobDetected()

Methods

void ALColorBlobDetectionProxy::setColor(int r, int g, int b, int colorThres)

Set the color of the blob to find (in RGB space).

Parameters:

• R – the Red component, from 0 to 255, of the RGB color to find.
• G – the Green component, from 0 to 255, of the RGB color to find.
• B – the Blue component, from 0 to 255, of the RGB color to find.
• colorThres – the threshold of the color match, from 0 to 255.

void ALColorBlobDetectionProxy::setObjectProperties(int minSize, float span, std::string shape)

There are two overloads of this function:

• ALColorBlobDetectionProxy::setObjectProperties
• ALColorBlobDetectionProxy::setObjectProperties without the shape argument.

Set some properties of the blob to find.

Parameters:

• minSize – the minimum size of the blob (in pixels)
• span – span of the object in meters (e.g. for a ball, the diameter)
• shape – shape of the object, use “Circle” if the object to find is circular, “Unknown” otherwise

void ALColorBlobDetectionProxy::setObjectProperties(int minSize, float span)

Set some properties of the blob to find. By using this function, the shape of the object is automatically set to “Unknown”.

Parameters:

• minSize – the minimum size of the blob (in pixels)
• span – span of the object in meters (e.g. for a ball, the diameter)

AL::ALValue ALColorBlobDetectionProxy::getCircle()

Retrieve the circle surrounding the blob.

Returns:the outer circle of the found blob as a vector of 3 values: x, y, radius in relative coordinates in the image (i.e. between 0 and 1).

For example in VGA (640x480), for a circle of 50 pixels in radius and a center located at (123, 71), this function would return [123/640, 71/480, 50/640].

bool ALColorBlobDetectionProxy::getAutoExposure()

Get the status of the auto exposure option of the camera.

Returns:false if deactivated, true if activated.

void ALColorBlobDetectionProxy::setAutoExposure(bool mode)

Set the status of the auto exposure option of the camera.

Parameters:

• mode – true: on, false: off.

Events

Event: "ALTracker/ColorBlobDetected"

callback(std::string eventName, AL::ALValue value, std::string subscriberIdentifier)

Raised when a color blob is detected.

Parameters:

• eventName (std::string) – “ALTracker/ColorBlobDetected”
• value – information related to the blob, with a structure that can be used with function ALTrackerProxy::trackEvent of the module ALTracker.
• subscriberIdentifier (std::string) –