Android Camera2 API-设置AE区域不起作用 [英] Android Camera2 API - Set AE-regions not working

问题描述

在我的Android Camera2 API项目中，我想为我的曝光计算"设置一个区域.不幸的是，它不起作用.另一方面，焦点"区域可以正常工作.

In my Camera2 API project for Android, I want to set a region for my Exposure Calculation. Unfortunately it doesn't work. On the other side the Focus region works without any problems.

设备:三星S7/Nexus 5

Device: Samsung S7 / Nexus 5

1.)CONTROL_AF_MODE&的初始值； CONTROL_AE_MODE

1.) Initial values for CONTROL_AF_MODE & CONTROL_AE_MODE

mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_AUTO);
mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON);

2.)创建MeteringRectangle列表

2.) Create the MeteringRectangle List

meteringFocusRectangleList = new MeteringRectangle[]{new MeteringRectangle(0,0,500,500,1000)};

3.)检查设备是否支持它，并设置CONTROL_AE_REGIONS(与CONTROL_AF_REGIONS相同)

3.) Check if it is supported by the device and set the CONTROL_AE_REGIONS (same for CONTROL_AF_REGIONS)

if (camera2SupportHandler.cameraCharacteristics.get(CameraCharacteristics.CONTROL_MAX_REGIONS_AE) > 0) {
      camera2SupportHandler.mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_REGIONS, meteringFocusRectangleList);
}

4.)告诉相机开始曝光控制

4.) Tell the camera to start Exposure control

camera2SupportHandler.mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER, CameraMetadata.CONTROL_AE_PRECAPTURE_TRIGGER_START);

CONTROL_AE_STATE始终处于CONTROL_AE_STATE_SEARCHING，但不使用配置的区域...

The CONTROL_AE_STATE is always in CONTROL_AE_STATE_SEARCHING, but doesn't use the configured regions...

推荐答案

经过长时间测试&开发我找到了答案.

After long testing & development I've found an answer.

1. 坐标系-Camera 1 API VS Camera 2 API

红色= CAM1;绿色= CAM2;如下图所示，蓝色矩形是Cam1可能的对焦/曝光区域的坐标.通过使用Cam2 API，必须首先查询高度和宽度的最大值.请在此处找到更多信息.

RED = CAM1; GREEN = CAM2; As shown in the image below, the blue rect are the coordinates for a possible focus/exposure area for the Cam1. By using the Cam2 API, there must be firstly queried the max of the height and the width. Please find more info here.

1. CONTROL_AF_MODE&的初始值CONTROL_AE_MODE:请参见上面的问题.

1. Initial values for CONTROL_AF_MODE & CONTROL_AE_MODE: See in the question above.

设置CONTROL_AE_REGIONS:请参见上面的问题.

Set the CONTROL_AE_REGIONS: See in the question above.

设置CONTROL_AE_PRECAPTURE_TRIGGER.

Set the CONTROL_AE_PRECAPTURE_TRIGGER.

//这是告诉相机开始自动曝光控制的方法

// This is how to tell the camera to start AE control

                CaptureRequest captureRequest = camera2SupportHandler.mPreviewRequestBuilder.build();
              camera2SupportHandler.mCaptureSession.setRepeatingRequest(captureRequest, captureCallbackListener, camera2SupportHandler.mBackgroundHandler);
                camera2SupportHandler.mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER, CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_START);
                camera2SupportHandler.mCaptureSession.capture(captureRequest, captureCallbackListener, camera2SupportHandler.mBackgroundHandler);

1. "captureCallbackListener"给出了AE控制的反馈(当然也包括AF控制)

因此，此配置适用于大多数Android手机.不幸的是，它不适用于三星S6/7.因此，我已经测试了他们的Camera SDK，可以在此处找到.

经过深入研究，我发现了配置字段"SCaptureRequest.METERING_MODE".通过将其设置为"SCaptureRequest.METERING_MODE_MANUAL"的值，AE区域也适用于三星手机.

After deep investigations I've found the config field ''SCaptureRequest.METERING_MODE''. By setting this to the value of ''SCaptureRequest.METERING_MODE_MANUAL'', the AE area works also the Samsung phones.

我将在 github 上尽快添加一个示例.

I'll add an example to github asap.

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