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

Question

我试图使用camera2 API我的代码在底部得到/计算设备相机的视野）。

在我上的银河S7尝试：

• 给定的传感器尺寸被3.2毫米X2.4毫米（使用SENSOR_INFO_PHYSICAL_SIZE）。
• 在这种情况下，我的计算HFOV是41.7°（给出的焦距是4.2mm），我通过实验证明是错误的。
• 各种规格文档提及了1/2.5" 传感器尺寸（5.76毫米X根据wikipedia4.29毫米） - 这将给我一个HFOV的68.9°，更接近我实验
• 在CameraCharacteristics的值似乎错误。

在三星Galaxy A3-2016相同的查询和实验是更确凿的，计算出HFOV似乎相匹配的实验之一。

有没有人的经验或数据共享有关的CameraCharacteristics读数的可靠性？

---

的代码，我习惯了这里查询CameraCharacteristics ::

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

开发Scanbot的（又名我带摄像头的工作就足够了）。

根据我的经验，没有任何关于Camera API的信息可靠，主要是因为这个API是硬件和供应商特定相机驱动程序上相对较薄的一层。换言之，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。