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Overlaping and IMU/GIMBAL angles

Hello ! I’m tryng to reduce the amount of photos to start processing, I’d do this by reducing the overlap i have. Is it correct to think that getting a lower overlap is going to reduce how much time it takes processing. I mean, a lower overlap could make a harder setp 1 for Pix4d, and maybe it won’t make it faster. Opinions ? What’s your experience ?

My second question is How does Pix4d know the angle of the camera(Nadir or oblique flight)? Does Pix4d know the IMU or GIMBAL angle? 

 

That’s all Thank you !!!

Hi Francisco. Yes reducing the number of images will lower processing times. You are also correct that lowering overlap too much can present problems with step 1 calibrations. You can try flying higher to increase the overlap without increasing the number of images. As long as the images are calibrating and the matching is adequate you should be fine. Pix4D uses the IMU data if it is available but the software can also calculate the orientation of the image using a what is called the “bundle adjustment” which occurs during step 1. The IMU mostly simplifies this operation which results in faster step 1 processing. 

Thanks for you answer Holden. Could you tell me where is the IMU information, i can’t find it on the EXIF, and pix4d doesn’t ask for it. How do i give this information to Pix4d?

The IMU data is usually stored in the image EXIF. In most cases, Pix4D can detect this info and loads it automatically for supported aircraft. This data can also be loaded from an external file as long as it is formatted correctly more info HERE.  Orientation info is not always visible when looking at image details depending on how you are looking at the image metadata. You can use a tool like ExifTool (HERE) to look more in-depth.