My images are captured in different tones and colors in the same survey. This affects the quality of the orthophotomosaic because it changes the way the vegetation is displayed.
We are aware of white balance (WB) issues with DJI cameras reported by some users. In the same dataset, images can appear hotter or colder with different shades. This depends on the temperature of the scene that is captured, meaning its content (different local sources of light) and the outdoor or indoor light conditions.
The WB parameter allows to compensate temperatures so that the color of the image is as close as possible to neutral which corresponds to sunlight at noon outdoor. At the moment, the white balance is set to automatic when flying an autopilot mission with our app (by default). For each image the temperature is adjusted by an algorithm that optimizes the colors. On iOS, there is a WB parameter that can be adjusted (Auto, Sunny, Cloud) while on Android, you can change the WB parameter in DJI GO (4) directly. It applies when flying with Pix4Dcapture on Android.
The problem is that in very rare cases, the DJI camera does not handle correctly the WB, and even tweaking the parameter might not be sufficient to ensure homogeneous temperature among the images of the flight. However, it does not affect the reconstruction in Pix4D desktop but it can affect the visual aspect of the orthomosaic and the colors of the points in the rayCloud.
The issue usually arises when the mapped area is particularly hot like earth or desert, meaning the colors are warmer than usually and with little contrast (few cool shades). Also changing light conditions because of clouds for instance, is difficult to handle by the camera. The best is to fly at noon with a sunny weather to ensure stable and constant lightning.
Ideally we would like DJI to add a tool to their SDKs that allows to set the correct color temperature to all images from the same flight. For now it is not possible to have the needed flexibility.
Hope it clarifies the situation.
Should I choose directly the DJI Go WB (non-automatic) balance? After, close the DJI Go and open the Pix4D Mapper?
On Android, you can:
- Change the WB settings in DJI GO (4).
- Quit the DJI app.
- Start Pix4Dcapture and make sure the DJI app is not running is the background.
The camera settings will apply even if you force quit.
I have also noted this issue and work in tropical Australia, where it is almost always hot! This is a constant issue for us. Thanks for the tips on how to compensate for this in the current circumstances, Julie.