|y4munsharp(1)||MJPEG tools manual||y4munsharp(1)|
- -v num
- Set verbosity level (0 = quiet, 1 = normal, 2 = debug) (default: 1)
- Print a suage summary and exit
- -L radius,amount,threshold
- Y' (luma) unsharp parameters. The radius and amount" arguments are floating point numbers. The threshold argument is an integer. (default: 3.0,0.3,4) -C radius,amount,threshold CbCr (chroma) unsharp parameters. The chroma is not processed unless this option is given. Arguments are the same type as for the -L option above. (default: none)
- Filtering can produce output outside the 16 to 240 range for Y' and 16 to 235 for CbCr. By default values outside the legal range are clipped/cored (values over 240 for Y' are set to 240 for example). Using -N the limits 0 and 255 are used instead.
y4munsharp -L 2.0,0.3,0 An aggressive setting: y4munsharp -L 5.0,0.5,0
The chroma is not processed for a several reasons: 1) The eye is much more sensitive to changes in brightness, 2) the chroma is usually subsampled and doesn't contribute much to the perceived sharpness of an image - so not processing the chroma provides a boost in speed of processing the image, and 3) possible artifacting - changes in Y' just make an image brighter/darker but changes in Cb or Cr can change colors and possibly lead to shifts in hue. Use the -C option to enable processing of the chroma planes.
Only progressive, top field first or bottom field first interlaced streams are handled. The mixed interlaced stream format is not supported.
|11 November 2004||MJPEG Tools Team|