# SoftBank Robotics documentation What's new in NAOqi 2.8?

# ALColorBlobDetection API

NAOqi Vision - Overview | API

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) –

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