視頻轉(zhuǎn)圖像
openCV
Add support for reading 4-channel BGRA frames from video
alalek commented on 19 Feb
There is already such option. To get RGBA frames (in case of RGBA native video stream) we should pass CAP_PROP_CONVERT_RGB=False
VideoCapture::set
What does disabling CV_CAP_PROP_CONVERT_RGB do?
根據(jù)以上說明，print(cap.set(cv2.CAP_PROP_CONVERT_RGB, False))輸出了false，失敗
ffmpeg
換一個思路，看看能否用ffmpeg實(shí)現(xiàn)
https://blog.csdn.net/pkueecser/article/details/8555261
ffmpeg -i target_video_test.mov -r 25 -f image2 target_video_test/%d.png
這個能work，下一步
圖像處理
imread
StackOverflow-How to load png images with 4 channels?
imread的時候加一個參數(shù)：
import cv2
im = cv2.imread("image.png", cv2.IMREAD_UNCHANGED)
img.shape變成了（x，x，4）需要改動一些代碼
imwrite
不需要任何改動
圖像轉(zhuǎn)視頻
Stackoverflow-Turn image sequence into video with transparency
To encode/import images with alpha to a video with alpha try:
ffmpeg -i %d.png -vcodec png z.mov. Quicktime will play that.
To decode/export a video with alpha to images with alpha try:ffmpeg -i z.mov -f image2 export2\%d.png
video2img和img2video都有，我為啥一開始沒搜到這篇。。。
ffmpeg -i target_video_test/%d.png -vcodec png target_video_test_new.mov
