如何自動對焦Android相機？

Question

我想在相機保持不動時自動對焦Android相機。 我正在尋找教程或示例如何做或至少小樣本，顯示我可以用來掛鈎這些事件的類。

Answer 1

對我來說，這是一種享受：

//set camera to continually auto-focus
Camera.Parameters params = c.getParameters();
//*EDIT*//params.setFocusMode("continuous-picture");
//It is better to use defined constraints as opposed to String, thanks to AbdelHady
params.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
c.setParameters(params);

Answer 2

嘗試使用Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO或Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE 。 見下文：

Camera.Parameters params = camera.getParameters();
if (params.getSupportedFocusModes().contains(
    Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO)) {
  params.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
}
camera.setParameters(params);

在嘗試使用之前測試手機是否支持您選擇的模式非常重要，否則setParameters()將拋出運行時異常。 （編輯代碼現在正常工作）

Answer 3

以下代碼適合我。

設置自動對焦（預覽類）：

Parameters params = camera.getParameters();
params.setFocusMode(Parameters.FOCUS_MODE_AUTO);
//some more settings
camera.setParameters(params);

如果自動對焦准備就緒，請調用相機拍攝照片（活動類別）：

public void butClick(View v){
    preview.camera.autoFocus(new AutoFocusCallback() {
        public void onAutoFocus(boolean success, Camera camera) {
            if(success){
                camera.takePicture(shutterCallback, rawCallback, jpegCallback);
            }
        }
    });
}

獲取圖片（活動類）：

PictureCallback jpegCallback = new PictureCallback() {
    public void onPictureTaken(byte[] data, Camera camera) {
        //do something
    }
};

Answer 4

看起來你應該連續自動對焦，如這里所討論的。

這里有一個問題 ，你可以參考。

Answer 5

這適用於預覽回調：

Camera.Parameters parameters = camera.getParameters();
if (parameters.getSupportedFocusModes().contains(
        Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO)) {
    parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
}
camera.setParameters(parameters);

Answer 6

你可以試試代碼：

ShutterCallback _pfnShutterCallback = new ShutterCallback() {

        @Override
        public void onShutter() {
            // TODO Auto-generated method stub

        }

    };

    PictureCallback _pfnRawPictureCallback = new PictureCallback() {

        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            // TODO Auto-generated method stub

        }
    };

    private AutoFocusCallback _pfnAutoFocusCallback = new AutoFocusCallback() {

        @Override
        public void onAutoFocus(boolean success, Camera camera) {
            // TODO Auto-generated method stub
            camera.autoFocus(null);
            camera.takePicture(_pfnShutterCallback, _pfnRawPictureCallback,
                    mPicture);

        }
    };
    private PictureCallback mPicture = new PictureCallback() {

        public void onPictureTaken(byte[] data, Camera camera) {
            new SavePhotoTask().execute(data);
            camera.startPreview();

        }
    };
class SavePhotoTask extends AsyncTask<byte[], String, String> {
// Process save file image
}

call capture： mCamera.autoFocus(autoFocusCallback);

您可以參考： http ： //android-er.blogspot.com/2011/01/start-camera-auto-focusing-autofocus.html