Barrel distortion or fixed?

My DJI drone can give me jpg and raw. The jpg’s are fixed from barrel distortion.

What is best to use?

Fixed jpg output or raw and make them jpg with distortion and all?

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If DJI uses fixed values for its corrections, then there is little harm in going either route. If they dynamically try to compute distortion on individual images, they will introduce intractable errors. Either way, the safest approach is to let ODM do all the corrections.


Have you saved images as raw? I’d be interested in knowing how much image quality loss the jpeg compression causes, and what sort of file size reduction ratio is obtained by using jpegs.
Can the raw images be easily viewed with regular image viewing software?

Ooh! That alone would be a fun test. Output them to RAW and then convert to PNG (thus lossless) and see if it makes a difference in reconstruction.


Usually about 1/8th - 1/10th the size or so, unless they’re using compressed RAW.

IQ is going to be difficult to ascertain. SOOC RAW is not going to look great, and (hopefully) won’t have any noise reduction nor sharpening applied (proper RAW, not “cooked”), either. The JPEGs should be pretty good minus some minor fine detail loss from NR.

You’d have to try and process the RAWs to be roughly equivalent.


Maybe I need to do some testing!


No, I did not. Next time I do!

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At least with my M2P, the raw images are only 960 X 640, so there wont be as much detail as with the JPGs, despite the IQ loss due to compression. They do save to the SD card very quickly though!

That should not be the case. RAW are meant to be dumps straight from the sensor, and that sensor is not 960x640.

Can you post one? It sounds like whatever you’re using to get that info is pulling the embedded JPEG thumbnail’s info.

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Here is one taken as DNG only, not JPG + DNG. Thumbnails are usually much smaller than 960 X 640

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Hunch: this is a true raw raw.

Bayer style sensors are interpolated to their full resolution, resulting in the final apparent resolution and megapixel count:

Truly raw data will be much lower apparent megapixels.