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

Question

我正在尝试使用camera2API（底部的代码）来获取/计算设备相机的FOV 。

在尝试使用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，我计算出的HFOV为41.7°（给定的焦距为4.2mm），经实验证明是错误的。
• 各种规格文档都提到了1 / 2.5英寸的传感器尺寸（根据维基百科，为5.76mm x 4.29mm ）-与我的实验相比，HFOV为68.9°。
• 中的值CameraCharacteristics似乎是错误的。

在三星Galaxy A3-2016上进行的相同查询和实验更具说服力，计算出的HFOV似乎与实验值相符。

有没有人可以分享有关CameraCharacteristics读数可靠性的经验或数据？

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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 的开发人员在这里（也就是我使用相机足够了）。

根据我的经验，关于相机 API 的任何东西都不可靠，主要是因为这个 API 是硬件和供应商特定相机驱动程序上的一个相对较薄的层。换句话说，API 的输出将取决于哪个供应商决定放置在那里，并且不受 Google 管理（与 Android SDK 的其余部分不同）。