This is probably the same question as https://www.reddit.com/r/kdenlive/comments/ik44o2/image_sequences_cutting_and_transparency/ ( and probably related to https://kdenlive.org/en/project/compositing-with-transparency/ )
Let's say I have an image sequence, with transparent background, and an element (here a rectangle) with a fill color with fading alpha/transparency; for instance, one generated with imagemagick
:
for ix in `seq 1 9`; do \
convert -size 640x480 xc:none \
-strokewidth 0 -fill "rgba( 255, 215, 30, 0.$ix )" \
-draw "rectangle 30,30 500,250" \
-strokewidth 2 -stroke blue -fill none \
-draw "rectangle 0,0 639,479" output$ix.png; \
done
It is very difficult obtaining a proper .gif animation directly from the above images; so I opened each one in an image viewer, took screenshot of the image viewer, and finally composed the screenshot images with convert -delay 0 -loop 0 Screenshot*.png animation_im.gif
, just to show what this image sequence looks like:
The animation above shows that there is a "gradual" or "continuous" "fade" of the color via the alpha channel.
Now, the problem is - typically, if I import this image sequence in kdenlive
(kdenlive-23.04.0-x86_64.AppImage
), and I render a video - the gradual fade is gone/disappears, and the only thing I get is a sudden/instantaneous appearance of the rectangle; similar to output of convert -delay 0 -loop 0 output*.png animation_im.gif
(ran on the original image sequence):
So, my question is: how do I preserve an alpha/transparency gradual/continuous fade in an image sequence, also in the rendered video output of kdenlive
?