Couple of questions re interpolation...

[Bussty]

That's weird tried to post this exact text on the DJI Frum and received this message.


Not sure why? Anyways here's what I was asking...

When I was testing the 7x as a high res image creator using stitching I received one 1x image with a DNG and jpeg out of camera and another 1x image with just the DNG out of the camera. The DNG's and jpeg had the same pixel width 5280 but to get a jpeg from the image that had only the DNG file I had to load it into Affinity photo and cropped it exactly as per the imbedded image in the DNG. The horizontal pixel count on that was only 4976 pixels and the total pixel count was only 19038176 (19 Mp.)
So I have some questions after doing that...

• So assuming the full DNG pixel width is 5280 and this is cropped to avoid vignetting and distorted corners (4976 pixels) how come the final jpeg out of the camera also shows 5280 pixels when it is cropped out of the full DNG? The full image from the DNG that Affinity shows is about 6-7% bigger than the imbedded image within the DNG file.
• Does this mean the jpegs coming out of the drone are interpolated back up to 5280 pixels width to appear as 20Mp images? (rather than 19 Mp)
• When taking video is the full sensor (less cropping similar to the jpegs) being used as the capture area and downsized to the desired video resolution or is there some slight telephoto effect when videoing i.e do you get the same field of view taking a 4x3 still compared to a 4x3 video?

Just curious really and I know the M2P had some scaling going on with it's video but have heard nothing about that with the Mavic 3?

Thanks

 

[Howard70]

Hello Bussty:

I can’t answer your question directly, but I have noticed a slight image composition shift between simultaneously recorded jpeg and DNG images when moving through them in Adobe Bridge on a large monitor (65” 4K television). The observed shift is more than a change in contrast or color, it appears to be a tiny alteration in the shape of items at the lower left and right corner of the images. I wondered what caused this and reading your question provides a possible explanation.

I suspect someone with a better understanding of the relative file structures and images with come along and help us both out.

Howard

 

[MavicAir2Marc]

I believe you would see a shift because the jpg applies a lens profile where the DNG (or RAW) file does not.

 

[Bussty]

I believe you would see a shift because the jpg applies a lens profile where the DNG (or RAW) file does not.

I think the embedded image in the DNG (so you can view it without developing) is a much smaller but same crop as the jpeg the drone creates but yes is a massive difference between DNG and jpeg when viewed in a Raw developer.