Question

我知道有很多问题询问你是否可以设置快门速度/ iso等等，而且似乎不可能......

但是，至少可以获得像快门速度，光圈和iso 这样的值吗？（不先拍照并扫描exif值......）

我的意思是对系统/硬件当前设置的值进行实时预览。

Answer 1

使用camera2，您可以查看通过CaptureResult回调生成的onCaptureCompleted个对象。

如果设备支持READ_SENSOR_SETTINGS功能，则CaptureResult SENSOR_EXPOSURE_TIME和SENSOR_SENSITIVITY字段将具有自动曝光例程选择的曝光和增益的当前值。

否则，您需要捕获JPEG图像并查看其EXIF，如其他答案所述。

Answer 2

关于iso值，请参阅此问题Android Camera API ISO Setting?，关于快门请参阅此帖https://stackoverflow.com/a/3550573/1860199

Answer 3

你可以使用Camera2 Api设置快门速度和曝光时间，我想，我不太了解它。但是，可以从拍摄照片时从相机获取的byte []数据中读取exif数据。

如果有人希望获得当前，而不是使用Camera1 Api或Camera2，ISO，曝光时间和快门速度值设置的那个。对于Camera1 Api，使用ExifInterface将数据写入FileOutputStream并读取exif数据。您可以使用此方法将每个元数据写入字节。获取数据后，您可以使用Bitmap.compress();

处理该文件并将图像压缩为png或jpg

     private PictureCallback mPicture = new PictureCallback() {

            @Override
            public void onPictureTaken(byte[] data, Camera camera) {
                long startTime = System.currentTimeMillis();

                File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
                FileOutputStream fos = null;
                Bitmap bitmap = null;

                if (pictureFile == null) {
                    return;
                }

                try {
                    fos = new FileOutputStream(pictureFile);
                    // TODO Writes Exif Data to image
                    System.out.println("************ EXIF ************");
                    fos.write(data);
                    ExifInterface exifInterface = new ExifInterface(pictureFile.getAbsolutePath());
                    String model = exifInterface.getAttribute(ExifInterface.TAG_MODEL);
                    String make = exifInterface.getAttribute(ExifInterface.TAG_MAKE);
                    String flash = exifInterface.getAttribute(ExifInterface.TAG_FLASH);
                    String exposureMode = exifInterface.getAttribute(ExifInterface.TAG_EXPOSURE_MODE);

                    String focalLengthString = exifInterface.getAttribute(ExifInterface.TAG_FOCAL_LENGTH);
                    String isoString = exifInterface.getAttribute(ExifInterface.TAG_ISO_SPEED_RATINGS);
                    String apertureString = exifInterface.getAttribute(ExifInterface.TAG_APERTURE_VALUE);
                    String exposureTimeString = exifInterface.getAttribute(ExifInterface.TAG_EXPOSURE_TIME);
                    String shutterSpeedString = exifInterface.getAttribute(ExifInterface.TAG_SHUTTER_SPEED_VALUE);

                    Double focalLength = exifInterface.getAttributeDouble(ExifInterface.TAG_FOCAL_LENGTH, 0);
                    Double iso = exifInterface.getAttributeDouble(ExifInterface.TAG_ISO_SPEED_RATINGS, 0);
                    Double aperture = exifInterface.getAttributeDouble(ExifInterface.TAG_APERTURE_VALUE, 0);
                    Double exposureTime = exifInterface.getAttributeDouble(ExifInterface.TAG_EXPOSURE_TIME, 0);
                    Double shutterSpeed = exifInterface.getAttributeDouble(ExifInterface.TAG_SHUTTER_SPEED_VALUE, 0);

                    System.out.println("CameraActivity model " + model);
                    System.out.println("CameraActivity make " + make);
                    System.out.println("CameraActivity flash " + flash);
                    System.out.println("CameraActivity exposureMode " + exposureMode);
                    System.out.println("CameraActivity focalLengthString " + focalLengthString + ", focalLength " + focalLength);
                    System.out.println("CameraActivity isoString " + isoString + ", iso " + iso);
                    System.out.println("CameraActivity apertureString " + apertureString + ", aperture " + aperture);
                    System.out.println("CameraActivity exposureTimeString " + exposureTimeString + ", exposureTime " + exposureTime);
                    System.out.println("CameraActivity shutterSpeedString " + shutterSpeedString + ", shutterSpeed " + shutterSpeed);

                    System.out.println("************ EXIF ************");

                } catch (FileNotFoundException e) {
                    System.out.println("CameraActivity onPictureTaken() File not found: " + e.getMessage());
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    try {
                        if (fos != null) {
                            fos.close();
                        }
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(pictureFile)));
                    fos = null;
                    pictureFile = null;

}

这些是我的设备获得的结果

 ************ EXIF ************
CameraActivity model General Mobile 4G Dual
CameraActivity make General Mobile
CameraActivity flash 24
CameraActivity exposureMode 0
CameraActivity focalLengthString 1150/1000, focalLength 1.15
CameraActivity isoString 262, iso 262.0
CameraActivity apertureString 260/100, aperture 2.6
CameraActivity exposureTimeString 0.03333333333333333, exposureTime 0.03333333333333333
CameraActivity shutterSpeedString 4906/1000, shutterSpeed 4.906

在android上获取当前的快门速度/ iso

3 个答案: