The idea to use a reference image to generate a histogram that we want all of the other images to match. To help achieve this end, I used an ImageMagick script called histmatch, generously provided by Fred Weinhaus (link: ). Obviously, this won't look great in your final video, so we're going to normalize the colors to a set distribution.įor an example, just compare the following two images (especially notice the trees, which are much lighter in the first example than the second): Sometimes images captured in a time lapse have very different histograms (especially if you have auto-aperture / shutter-speed enabled), and this can make things look "jumpy" from frame to frame. Note: this step might not be necessary in your situation, but it greatly improved the quality of the final product for me. Mogrify -resize 600x -write RESIZED_PHOTO_DIRECTORY/$FILE $FILE \ To start, make sure you're in the directory with all of your photos. This will resize your images to a preferred resolution (in this case, 1280x720), and will potentially crop off the sides or top in the process. If you're like me, and you don't care too much about maintaining the current aspect ratio, here's what you can do. Since I planned to upload my video to YouTube, I referenced a handy page they have that lists out their preferred resolutions, codecs, and formats for upload ( ). Therefore, the first thing you should probably do is check the size of your images and, if necessary, resize them to be a bit smaller so they will play more nicely with FFmpeg and any other image manipulation that you're going to do. During my first tests, making movies from images this large gave really inconsistent results and took a long time to create, with not much extra benefit. ResizingĮven though I turned off RAW on the X100T, the images were still pretty huge (4896x3264). Note: Everything in this tutorial assumes that you have a current copy of ImageMagick and FFmpeg installed on your machine. So, as any self-respecting engineer would, I set out to create a time-lapse using only my trusty command-line tools: FFmpeg and ImageMagick. After all was said and done, I ended up with 400 images depicting clouds moving over a mountain peak and not much idea of what to do with them. Yesterday, I set it up on an interval timer and pointed it right towards Rainbow Mountain, which faces the patio in the kitchen of the little condo unit we're renting out. Expecting some beautiful landscapes and weather, I brought my newly acquired X100T to take some nice photos. We're vacationing in Whistler, BC right now as "endurance spectators" to my father-in-law's 3rd Ironman triathlon. Making a time-lapse on the command line using FFmpeg and ImageMagick Sunday, July 26, 2015
0 kommentar(er)
