Closed swtyree closed 1 year ago
Hi @swtyree and thanks for using Record3D :).
Apart from increased file size (which isn't necessarily a problem, as you mentioned), there is the issue of ensuring real-time performance when processing (nearly) lossless images. I'll take a look into this to see how performance would be affected across different devices under low levels of compression and if it turns out there is a negligible performance drop, I will try to add such option into a future update.
P.S. The lossless USB streaming (USB Streaming RGB quality
exactly at 100
) uses PNG instead of JPEG, so if your use case requires lossless quality, then I don't think it would be possible to implement this feature in real-time (PNG encoding isn't hardware-accelerated).
Thanks, @marek-simonik! I think a range of JPEG compression settings would be acceptable. For instance, I tried settings from 70-100 for a frame from a recent lossless capture (cv2.imwrite(filename, img, [cv2.IMWRITE_JPEG_QUALITY, quality])
). Beyond 75 or 80, the visual differences were barely perceptible, while the file sizes were noticeably smaller:
quality_070.jpg 28K
quality_075.jpg 31K
quality_080.jpg 36K
quality_085.jpg 43K
quality_090.jpg 56K
quality_095.jpg 86K
quality_100.jpg 188K
quality____.png 428K
OK, if (limited range of) JPEG compression settings is an acceptable compromise for you, then I will add such option into the next Record3D update.
Thank you! Do you have an estimate for when the next update will be pushed?
The next Record3D update should be on the App Store next week (or earlier).
Hi @marek-simonik, thanks for the fantastic app! I use depth cameras for computer vision research, and the ability to capture RGB-D videos without being tethered to a computer is a game-changer.
My one complaint is that the JPEG compression rate for in-app captures leaves a lot of artifacts. Are there any plans to expose that setting in the future? I've made a few captures using the USB interface with lossless RGB streaming, and the resulting images are much better. I realize that a higher setting will significantly increase file sizes on the iPad, but that is something I am willing to work around.
Thanks!