> For the complete documentation index, see [llms.txt](https://docs.recognito.vision/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.recognito.vision/face-recognition-sdk/integration-guide/flutter/api-reference.md). # API Reference ### setActivation {% code overflow="wrap" %} ```dart Future setActivation(String license) ``` {% endcode %}


Name	setActivation
Description	Activate SDK
Input	license: The license string
Output	The SDK activation status code. 0: Success Non-zero: Activation failed

### init {% code overflow="wrap" %} ```dart Future init() ``` {% endcode %}


Name	init
Description	Initiate SDK
Input	None
Output	The SDK initialization status code. 0: Success -1: License Key Error -2: License AppID Error -3: License Expired -4: Activate Error -5: Initialize SDK Error

### setParam {% code overflow="wrap" %} ```dart Future setParam(Meap params) ``` {% endcode %}


Name	setParam
Description	Set Face Detection parameters
Input	params face detection parameters `'check_liveness_level' 0: liveness v1 -> more accurate model 1: liveness v2-fast -> lighter model`
Output	None

### extractFaces {% code overflow="wrap" %} ```kotlin Future extractFaces(String imagePath) ``` {% endcode %}


Name	extractFaces
Description	Detect and extract face templates from image file
Input	imagePath : Image file path
Output	Face detection result `{ "x1": face.x1, "y1": face.y1, "x2": face.x2, "y2": face.y2, "liveness": face.liveness, "yaw": face.yaw, "roll": face.roll, "pitch": face.pitch, "templates": templates, "faceJpg": faceJpg, "frameWidth": bitmap!!.width, "frameHeight": bitmap!!.height }`

### similarityCalculation {% code overflow="wrap" %} ```dart Future similarityCalculation( Uint8List templates1, Uint8List templates2) ``` {% endcode %}


Name	similarityCalculation
Description	Calculate similarity between two face features
Input	templates1: The first face template templates2: The second face template
Output	A float value representing the similarity score between the two face templates The score ranges from 0.0 to 1.0 Default Threshold is 0.8

### onFaceDetected ```dart void onFaceDetected(faces) ```


Name	onFaceDetected
Description	callback function for face detection on camera stream
Input	None
Output	Face detection result in camera frame

callback function definition ```java @Override public void onFrame(Bitmap bitmap) { ArrayList> faceBoxesMap = new ArrayList>(); FaceDetectionParam param = new FaceDetectionParam(); param.check_liveness = true; param.check_liveness_level = FaceDetectionFlutterView.livenessDetectionLevel; List faceBoxes = FaceSDK.faceDetection(bitmap, param); for(int i = 0; i < faceBoxes.size(); i ++) { FaceBox faceBox = faceBoxes.get(i); byte[] templates = FaceSDK.templateExtraction(bitmap, faceBox); Bitmap faceImage = Utils.cropFace(bitmap, faceBox); ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); faceImage.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream); byte[] faceJpg = byteArrayOutputStream.toByteArray(); HashMap e = new HashMap(); e.put("x1", faceBox.x1); e.put("y1", faceBox.y1); e.put("x2", faceBox.x2); e.put("y2", faceBox.y2); e.put("liveness", faceBox.liveness); e.put("yaw", faceBox.yaw); e.put("roll", faceBox.roll); e.put("pitch", faceBox.pitch); e.put("templates", templates); e.put("faceJpg", faceJpg); e.put("frameWidth", bitmap.getWidth()); e.put("frameHeight", bitmap.getHeight()); faceBoxesMap.add(e); } Message message = new Message(); message.what = 1; message.obj = faceBoxesMap; channelHandler.sendMessage(message); } ``` --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.recognito.vision/face-recognition-sdk/integration-guide/flutter/api-reference.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.