android 实现贴纸功能 手机贴纸模板

前言

在这个美即真理、全民娱乐的时代，可爱有趣的人脸贴纸在各大美颜软件中得到了广泛的应用，现在已经不仅局限于相机美颜类软件中，在社交、娱乐类的app中对人脸贴纸、AR贴纸的需求也非常广泛。本文详细介绍了集成华为HMS ML kit人脸识别实现2d贴纸的集成过程，在后面的文章中我们还会介绍3D贴纸的开发过程，欢迎大家关注哦~

场景

在美颜相机、美图app以及社交类app(如抖音、微博、微信)等需要对拍照，或者对照片进行处理的app都会构建自己特有的贴纸的需求。

开发前准备

在项目级gradle里添加华为maven仓

打开AndroidStudio项目级build.gradle文件

增量添加如下maven地址：

buildscript {
{
maven {url 'http://developer.huawei.com/repo/'}
}
}
allprojects {
repositories {
maven { url 'http://developer.huawei.com/repo/'}
}
}

在应用级的build.gradle里面加上SDK依赖

// Face detection SDK.
implementation 'com.huawei.hms:ml-computer-vision-face:2.0.1.300'
// Face detection model.
implementation 'com.huawei.hms:ml-computer-vision-face-shape-point-model:2.0.1.300'

在AndroidManifest.xml文件里面申请相机、访问网络和存储权限

代码开发关键步骤

设置人脸检测器

MLFaceAnalyzerSetting detectorOptions;
detectorOptions = new MLFaceAnalyzerSetting.Factory()
.setFeatureType(MLFaceAnalyzerSetting.TYPE_UNSUPPORT_FEATURES)
.setShapeType(MLFaceAnalyzerSetting.TYPE_SHAPES)
.allowTracing(MLFaceAnalyzerSetting.MODE_TRACING_FAST)
.create();
detector = MLAnalyzerFactory.getInstance().getFaceAnalyzer(detectorOptions);

这里我们通过相机回调拿到相机帧数据,并通过调用人脸检测器拿到人脸轮廓点后写入FacePointEngine供贴纸滤镜使用@Override

public void onPreviewFrame(final byte[] imgData, final Camera camera) {
int width = mPreviewWidth;
int height = mPreviewHeight;
long startTime = System.currentTimeMillis();
//设置前后摄方向一致
if (isFrontCamera()){
mOrientation = 0;
}else {
mOrientation = 2;
}
MLFrame.Property property =
new MLFrame.Property.Creator()
.setFormatType(ImageFormat.NV21)
.setWidth(width)
.setHeight(height)
.setQuadrant(mOrientation)
.create();
ByteBuffer data = ByteBuffer.wrap(imgData);
// 调用人脸检测接口
SparseArray faces = detector.analyseFrame(MLFrame.fromByteBuffer(data,property));
//判断是否获取到人脸信息
if(faces.size()>0){
MLFace mLFace = faces.get(0);
EGLFace EGLFace = FacePointEngine.getInstance().getOneFace(0);
EGLFace.pitch = mLFace.getRotationAngleX();
EGLFace.yaw = mLFace.getRotationAngleY();
EGLFace.roll = mLFace.getRotationAngleZ() - 90;
if (isFrontCamera())
EGLFace.roll = -EGLFace.roll;
if (EGLFace.vertexPoints == null) {
EGLFace.vertexPoints = new PointF[131];
}
int index = 0;
// 获取一个人的轮廓点坐标并转化到openGL归一化坐标系下的浮点值
for (MLFaceShape contour : mLFace.getFaceShapeList()) {
if (contour == null) {
continue;
}
List points = contour.getPoints();
for (int i = 0; i < points.size(); i++) {
MLPosition point = points.get(i);
float x = ( point.getY() / height) * 2 - 1;
float y = ( point.getX() / width ) * 2 - 1;
if (isFrontCamera())
x = -x;
PointF Point = new PointF(x,y);
EGLFace.vertexPoints[index] = Point;
index++;
}
}
// 插入人脸对象
FacePointEngine.getInstance().putOneFace(0, EGLFace);
// 设置人脸个数
FacePointEngine.getInstance().setFaceSize(faces!= null ? faces.size() : 0);
}else{
FacePointEngine.getInstance().clearAll();
}
long endTime = System.currentTimeMillis();
Log.d("TAG","Face detect time: " + String.valueOf(endTime - startTime));
}

ML kit接口返回的人脸轮廓点情况如图所示：

介绍如何设计贴纸,首先看一下贴纸数JSON数据定义public class FaceStickerJson {

public int[] centerIndexList; // 中心坐标索引列表，有可能是多个关键点计算中心点
public float offsetX; // 相对于贴纸中心坐标的x轴偏移像素
public float offsetY; // 相对于贴纸中心坐标的y轴偏移像素
public float baseScale; // 贴纸基准缩放倍数
public int startIndex; // 人脸起始索引，用于计算人脸的宽度
public int endIndex; // 人脸结束索引，用于计算人脸的宽度
public int width; // 贴纸宽度
public int height; // 贴纸高度
public int frames; // 贴纸帧数
public int action; // 动作，0表示默认显示，这里用来处理贴纸动作等
public String stickerName; // 贴纸名称，用于标记贴纸所在文件夹以及png文件的
public int duration; // 贴纸帧显示间隔
public boolean stickerLooping; // 贴纸是否循环渲染
public int maxCount; // 最大贴纸渲染次数
...
}

我们制作猫耳贴纸JSON文件,通过人脸索引找到眉心84号点和鼻尖85号点分别贴上耳朵和鼻子,然后把它和图片都放在assets目录下{

"stickerList": [{
"type": "sticker",
"centerIndexList": [84],
"offsetX": 0.0,
"offsetY": 0.0,
"baseScale": 1.3024,
"startIndex": 11,
"endIndex": 28,
"width": 495,
"height": 120,
"frames": 2,
"action": 0,
"stickerName": "nose",
"duration": 100,
"stickerLooping": 1,
"maxcount": 5
}, {
"type": "sticker",
"centerIndexList": [83],
"offsetX": 0.0,
"offsetY": -1.1834,
"baseScale": 1.3453,
"startIndex": 11,
"endIndex": 28,
"width": 454,
"height": 150,
"frames": 2,
"action": 0,
"stickerName": "ear",
"duration": 100,
"stickerLooping": 1,
"maxcount": 5
}]
}

这里渲染贴纸纹理我们使用GLSurfaceView,使用起来比TextureView简单, 首先在onSurfaceChanged实例化贴纸滤镜,传入贴纸路径并开启相机@Override

public void onSurfaceCreated(GL10 gl, EGLConfig config) {
GLES30.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
mTextures = new int[1];
mTextures[0] = OpenGLUtils.createOESTexture();
mSurfaceTexture = new SurfaceTexture(mTextures[0]);
mSurfaceTexture.setOnFrameAvailableListener(this);
//将samplerExternalOES 输入到纹理中
cameraFilter = new CameraFilter(this.context);
//设置assets目录下人脸贴纸路径
String folderPath ="cat";
stickerFilter = new FaceStickerFilter(this.context,folderPath);
//创建屏幕滤镜对象
screenFilter = new BaseFilter(this.context);
facePointsFilter = new FacePointsFilter(this.context);
mEGLCamera.openCamera();
}

然后在onSurfaceChanged初始化贴纸滤镜@Override

public void onSurfaceChanged(GL10 gl, int width, int height) {
Log.d(TAG, "onSurfaceChanged. width: " + width + ", height: " + height);
int previewWidth = mEGLCamera.getPreviewWidth();
int previewHeight = mEGLCamera.getPreviewHeight();
if (width > height) {
setAspectRatio(previewWidth, previewHeight);
} else {
setAspectRatio(previewHeight, previewWidth);
}
// 设置画面的大小,创建FrameBuffer,设置显示尺寸
cameraFilter.onInputSizeChanged(previewWidth, previewHeight);
cameraFilter.initFrameBuffer(previewWidth, previewHeight);
cameraFilter.onDisplaySizeChanged(width, height);
stickerFilter.onInputSizeChanged(previewHeight, previewWidth);
stickerFilter.initFrameBuffer(previewHeight, previewWidth);
stickerFilter.onDisplaySizeChanged(width, height);
screenFilter.onInputSizeChanged(previewWidth, previewHeight);
screenFilter.initFrameBuffer(previewWidth, previewHeight);
screenFilter.onDisplaySizeChanged(width, height);
facePointsFilter.onInputSizeChanged(previewHeight, previewWidth);
facePointsFilter.onDisplaySizeChanged(width, height);
mEGLCamera.startPreview(mSurfaceTexture);
}

最后通过onDrawFrame把贴纸绘制到屏幕@Override

public void onDrawFrame(GL10 gl) {
int textureId;
// 清除屏幕和深度缓存
GLES30.glClear(GLES30.GL_COLOR_BUFFER_BIT | GLES30.GL_DEPTH_BUFFER_BIT);
//更新获取一张图
mSurfaceTexture.updateTexImage();
//获取SurfaceTexture转化矩阵
mSurfaceTexture.getTransformMatrix(mMatrix);
//设置相机显示转化矩阵
cameraFilter.setTextureTransformMatrix(mMatrix);
//绘制相机纹理
textureId = cameraFilter.drawFrameBuffer(mTextures[0],mVertexBuffer,mTextureBuffer);
//绘制贴纸纹理
textureId = stickerFilter.drawFrameBuffer(textureId,mVertexBuffer,mTextureBuffer);
//绘制到屏幕
screenFilter.drawFrame(textureId , mDisplayVertexBuffer, mDisplayTextureBuffer);
if(drawFacePoints){
facePointsFilter.drawFrame(textureId, mDisplayVertexBuffer, mDisplayTextureBuffer);
}
}

这样我们的贴纸就画到人脸上了.

Demo效果

源码

原作者：旭小夜