# ALColorBlobDetection API ¶

NAOqi Vision - Overview | API

Namespace : AL



#include <alproxies/alcolorblobdetectionproxy.h>



## Method list ¶

class  ALColorBlobDetectionProxy 

## 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:

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 ) –