# ALColorBlobDetection API¶

NAOqi Vision - Overview | API

Namespace : AL


#include <alproxies/alcolorblobdetectionproxy.h>



## 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) –