2
1
I would like to use Tesseract OCR with a video.
With ffmpeg I can export some (.jpeg
) images from a video. Can I convert a .jpeg
into a valid .tiff
or export directly .tiff
images from the video with ffmpeg?
2
1
I would like to use Tesseract OCR with a video.
With ffmpeg I can export some (.jpeg
) images from a video. Can I convert a .jpeg
into a valid .tiff
or export directly .tiff
images from the video with ffmpeg?
4
Converting to TIFF
You can convert a JPEG to TIFF:
ffmpeg -i input.jpeg -pix_fmt rgba output.tiff
Or from a video:
ffmpeg -i input.mp4 -pix_fmt rgba out%05d.tiff
What's important is specifying the RGBA colorspace. Keeping the YUV 4:2:0 colorspace from video will produce TIFF files that cannot be opened in most programs (even though the YCbCr* colorspace is allowed).
How to compress output
By default this produces uncompressed TIFF images. You can choose a different compression algorithm using the -compression_algo
option:
ffmpeg -i input.jpeg -pix_fmt rgb24 -compression_algo lzw output.tiff
Valid options are packbits
, raw
, lzw
and deflate
(see ffmpeg -h encoder=tiff
).
* YCbCr refers to what in video compression is usually known as YUV
Wow, amazing! That solve my problem! :) Thank you very much! – Tenaciousd93 – 2014-10-20T06:57:19.923
Using this method, I end up with TIFFs that are huge compared to outputting (say) PNG and then converting to TIFF using ImageMagick; something that 0.5MB vs 3MB. Do you know why that is? Presumably something to do with compression. How do I enable lossless compression on the TIFFs?\ – Ray – 2018-03-06T10:50:46.137
1@Ray See updated answer, there are some options for specifying compression algorithms. – slhck – 2018-03-06T11:08:12.360
I think you can export directly to tiff from ffmpeg... http://stackoverflow.com/questions/1717331/convert-video-file-to-tiff-with-ffmpeg-dll-or-avcodec-dll-is-on-the-fly-possi
– Kinnectus – 2014-10-17T07:45:08.583Hello, thank you for your reply! No, the links in that accepted answer are broken and the other answers didn't export correcly
.tiff
images. – Tenaciousd93 – 2014-10-17T09:18:41.653