Question

我正在尝试使用底部的camera2 API来获取/计算设备摄像机的FOV。

我尝试使用Galaxy S7时：

给定的传感器尺寸为3.2mm x 2.4mm（使用SENSOR_INFO_PHYSICAL_SIZE）。
在这种情况下，我计算的HFOV是41.7°（给定的焦距是4.2mm），我通过实验证明这是错误的。
各种规格文件提到1 / 2.5“传感器尺寸（5.76mm x 4.29mm根据wikipedia） - 这将给我一个68.9°的HFOV，更接近我的实验。
CameraCharacteristics中的值似乎有误。

三星Galaxy A3-2016上的相同查询和实验更具决定性，计算出的HFOV似乎与实验相符。

是否有人有经验或数据可以分享CameraCharacteristics读数的可靠性？

我用来查询CameraCharacteristics ::

的代码

CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraID);
if (characteristics.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_FRONT)
    continue;

int support = characteristics.get(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL);
if( support == CameraMetadata.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY )
    Log.d("mr", "Camera " + cameraID + " has LEGACY Camera2 support");
else if( support == CameraMetadata.INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED )
    Log.d("mr", "Camera " + cameraID + " has LIMITED Camera2 support");
else if( support == CameraMetadata.INFO_SUPPORTED_HARDWARE_LEVEL_FULL )
    Log.d("mr", "Camera " + cameraID + " has FULL Camera2 support");
else
    Log.d("mr", "Camera " + cameraID + " has unknown Camera2 support?!");

// voir http://myandroidarchive.tistory.com/5 pour le query android
// voir http://paulbourke.net/miscellaneous/lens/ pour les maths
// include every focal length supported by the camera device, in ascending order.
float[] focalLengths = characteristics.get(CameraCharacteristics.LENS_INFO_AVAILABLE_FOCAL_LENGTHS);
SizeF sensorSize = characteristics.get(CameraCharacteristics.SENSOR_INFO_PHYSICAL_SIZE);

float w = 0.5f * sensorSize.getWidth();
float h = 0.5f * sensorSize.getHeight();
Log.d("mr", "Camera " + cameraID + " has sensorSize == " + Float.toString(2.0f*w) + ", " + Float.toString(2.0f*h));
for (int focusId=0; focusId<focalLengths.length; focusId++) {
    float focalLength = focalLengths[focusId];
    float horizonalAngle = (float) Math.toDegrees(2 * Math.atan(w / focalLength));
    float verticalAngle = (float) Math.toDegrees(2 * Math.atan(h / focalLength));
    Log.d("mr", "Camera " + cameraID + "/f" + focusId + " has focalLength == " + Float.toString(focalLength));
    Log.d("mr", "  * horizonalAngle == " + Float.toString(horizonalAngle));
    Log.d("mr", "  * verticalAngle == " + Float.toString(verticalAngle));
}

Answer 1

Scanbot的开发人员（也就是我使用相机足够了）。

根据我的经验，Camera API的任何内容都不可靠，因为这个API在硬件和供应商特定的相机驱动程序上是一个相对薄的层。换句话说，API的输出将取决于供应商决定放在哪里，而不是（与Android SDK的其他部分不同）由Google管理。

Android camera2 CameraCharacteristics API对传感器尺寸的可靠性如何？

1 个答案: