在Android中镜像前置摄像头 [英] Mirror the front facing camera in Android

问题描述

在Android中使用前置摄像头拍照时，预览会沿Y轴反射，使所看到的图像看起来就像用户在照镜子一样。我想撤消此效果（应用第二次反射）或只是停止自动完成的操作。

When you take a picture with the front facing camera in Android the preview is reflected along the Y axis to make the image seen appear as if the user was looking in the mirror. I want to undo this effect (apply a second reflection) or just stop the one thats done automatically.

我虽然要使用此功能：

Camera mCamera;
....
mCamera.setPreviewCallback(...);

但是我真的不知道该如何处理

But I dont really know what to do with the overriding of

onPreviewFrame(byte[] data, Camera camera){...}

实现我所描述的最佳方法是什么？

注意尝试将这种效果应用于实时预览，而不是已拍摄的图像。

推荐答案

打开时首先使用Camera.open（）您的相机实例，应该使用Camera.open（getSpecialFacingCamera（））

First when you open your camera instance with Camera.open() you should open front camera with Camera.open(getSpecialFacingCamera())

private int getSpecialFacingCamera() {
    int cameraId = -1;
    // Search for the front facing camera
    int numberOfCameras = Camera.getNumberOfCameras();
    for (int i = 0; i < numberOfCameras; i++) {
        Camera.CameraInfo info = new Camera.CameraInfo();
        Camera.getCameraInfo(i, info);
        if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
            cameraId = i;
            break;
        }
    }
    return cameraId;
}

然后在您的回调方法中，将相机数据转换为图像
您可以使用此代码使它保持正常

Then in your callback method where camera data is converting in to image you can use this code to keep it normal

public void onPictureTaken(byte[] data, Camera camera){
            Bitmap newImage = null;
            Bitmap cameraBitmap;
            if (data != null) {
                cameraBitmap = BitmapFactory.decodeByteArray(data, 0, (data != null) ? data.length : 0);
                if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
                    // use matrix to reverse image data and keep it normal
                    Matrix mtx = new Matrix();
                    //this will prevent mirror effect
                    mtx.preScale(-1.0f, 1.0f);
                    // Setting post rotate to 90 because image will be possibly in landscape
                    mtx.postRotate(90.f);
                    // Rotating Bitmap , create real image that we want
                    newImage = Bitmap.createBitmap(cameraBitmap, 0, 0, cameraBitmap.getWidth(), cameraBitmap.getHeight(), mtx, true);
                }else{// LANDSCAPE MODE
                    //No need to reverse width and height
                    newImage = Bitmap.createScaledBitmap(cameraBitmap, screenWidth, screenHeight, true);
                    cameraBitmap = newImage;
                }
            }
        }

您可以在画布中传递newImage并创建jpeg图像并将其保存在设备上。
不要忘了Api 21级不建议使用相机...

you can pass newImage in canvas and create jpeg image and save it on device. Do not forgot Camera is deprecated in Api level 21...

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