Chapter 9: Camera

【Introduction】

• This article will conclude a general manual for camera module.
• API:https://developer.dji.com/api-reference-v5/android-api/Components/IKeyManager/Key_Camera_CameraKey.html

【Camera Mode】

• Every camera has different camera mode. The camera mode can be set by KeyCameraMode. You can use KeyCameraModeRange to check which camera mode does it support?
• Under the PHOTO_NORMAL mode, by default every lenses from the camera will take photos. You can use KeyCaptureCameraStreamSettings to choose which lens to take photos.
• Under the VIDEO_NORMAL mode, by default every lenses from the camera will record videos. You can use KeyRecordCameraStreamSettings to choose which lens to record videos.
• Under the PHOTO_HYPER_LIGHT mode, the camera will adjust the exposure settings automatically according to the dark environment. This will result a clearer captured image and only valid when the zoom lens has a magnification greater than 5X.
• Under PHOTO_INTERVAL mode, you can make the camera to shoot photos in a time interval. You can use KeyPhotoIntervalShootSettings to set the time interval parameters. The count means how many photos to take in total. The time means time interval and it must be greater than 2. Then you can use KeyStartShootPhoto to start shooting and use KeyStopShootPhoto to stop shooting.
• Under PHOTO_SUPER_RESOLUTION mode, you can use KeySuperResolutionCaptureArea to set the region for super resolution capture. You can use KeySuperResolutionInfo to monitor the super resolution capture status. After all seetings are done, you can use KeyStartShootPhoto to start shooting and KeyStopShootPhoto to stop shooting.
• Under the PHOTO_PANORAMA mode, you can use KeyPhotoPanoramaMode to set the parameters of Panorama capture and use KeyPhotoPanoramaProgress to monitor the capture progress. After all settings done, you can use KeyStartShootPhoto to start shooting and KeyStopShootPhoto to stop shooting. The aircraft must fly in the air to shoot. You have to use 3rd party library to joint and render those photos together, MSDK will not provide any technical support. 
  

【Exposure】

• You need to know the current display video stream is the lens you want to configure. The thermal lens does not support the exposure mode. You can use KeyExposureMode to set the exposure mode and you can use KeyExposureModeRange to check which camera lens does support the exposue mode including its detailed settings.
• Only the exposure mode is PROGRAM and you can use KeyExposureCompensation to set the exposure compensation. You can use KeyExposureCompensationRange to check the range of available exposure compensation.
• Only the exposure mode is PROGRAM and you can use KeyAELockEnabled to set the lock of auto exposure. This setting will lock the exposure settings. It is used to faces the pure colour objects.
• Only the exposue mode is MANUAL and then you can set KeyISO and KeyShutterSpeed, some lenses may not support this settings and you need to check KeyISORange and KeyShutterSpeedRange in advanced.

【Zoom】

• You need to ensure the current display video steam is the lens you want to zoom. If the current display lens is Zoom, you can call KeyCameraZoomRatios to set the hybrid zoom rato for the zoom lens. The zoom range is 2-200 and the minimum accuracy is 0.1. If the current display lens is Thermal, you can call KeyThermalZoomRatios to set the thermal lens zoom ratio as 1X, 2X, 4X and 8X.
• You can call KeyCameraZoomFocalLength to get the hybrid focal length of the zoom lens.
• If you set the KeyCameraZoomRatios as 9 and you get 8.997 after getting this key again, this is a normal behaviour. This is because the zoom ratio is still running by the focal length step so many times the zoom ratio is not an integer.
  

【Focus】

• You can use KeyCameraFocusMode to set the focus mode.
• MANUAL means manual focus, you need to set the focus ring KeyCameraFocusRingValue to focus. The MSDK does not support the equation for how to calculate the focus ring. We suggest you build up a dragging bar to set the focus ring and you can check if the camera is focus on the object by viewing it.
• AF means auto focus, you can use KeyCameraFocusTarget to auto focus on a specific spot on the screen.
• AFC means auto focus continuously. Under this mode, the camera will use the center screen spot as the focus target. When the focus object is moving, the camera will adjust the focus ring automatically to ensure the object image is clear.

【Thermal】

• If you want to use or configure the thermal lens, the current video display must be set to THERMAL.
• Use KeyThermalTemperatureMeasureMode as SPOT can make the thermal lens enter spot measurement mode, you can use KeyThermalSpotMetersurePoint to set the measureing spot on the screen and listen the a key to monitor the temperature change.
• Use KeyThermalTemperatureMeasureMode as REGIONcan make the thermal lens enter region measurement mode, you can use KeyThermalRegionMetersureTemperature to set the measureing region on the screen and listen the a key to monitor the temperature change.
• Use KeyThermalGainMode will chang ethe gain mode of thermal lens. The thermal lens will be highly sensitive to temperature change but the valid temperature measurement range is narrow when choosing high gain mode. The thermal lens will be low sensitive to temperature change but the valid temperature measurement range is wide when choosing low gain mode.
• Set the KeyThermalPalette will change the thermal paletter of the thermal lens. The colors represent temperature and it is divided into 256 diffrent color gradations and show on 8 bit JPEG iamge and MP4 video. Every thermal palette has different map of color gradations. The MSDK does not provide the map of color gradation and temperature.
• Set the KeyThermalIsothermEnabled will enable or disable isotherms. Turn on the isotherm function to see objects in the specified temperature range more intuitively. The temperature range is set by two thresholds of high temperature and low temperature. When disabled, all 256 values (8-bits) are dedicated to the temperature histogram of the scene. When enabled, only 128 values (0-127) are mapped linearly to temperature. Then three bands 128-175, 176-223 and 224-255 can be mapped to the user defined temperatures to highlight them to the user. Using some of the false color palettes (like RainbowIso) results in a thermal image that is grey scale except for three specific bands highlighted by either reds, blues or greens.
• Set the a will change the thermal display mode. It only has THERMAL_ONLY or PIP.
  

【FAQ】

Q：How to set the file format of photo or video?

A：You can use KeyPhotoFileFormatRange and KeyVideoFileFormatRange to check the range of supporting file format for this camera, then call KeyPhotoFileFormat and KeyVideoFileFormat to set the file format.

Q：How to know if a photo capture is done?

A：A new media file will be generated when a photo capture is done. You can setup a listener to monitor the KeyNewlyGeneratedMediaFile.

Q：How to use the laser on H20 series camera?

A：After set the KeyLaserWorkMode to OPEN_ON_DEMAND, you can call KeyLaserMeasureEnabled to enable the laser measurement. Then setup a listener to monitor the KeyLaserMeasureInformation to measure the laser measurement.

Q：How to set the video display?

A：You can use KeyCameraVideoStreamSourceRange to know the video display range of this camera and use KeyCameraVideoStreamSource to set.

Q：How to get camera's heading?

A：The camera heading is actually the gimbal heading, please see this article:Chapter 9: Camera