Fixed colorthres/erase/extract/gaussianblur/gradient/motionblur/motiondetect/noise/psychedelic/sharpen filters.

input and output picture pitches may not be equal (corruptions or segfaults).
(cherry picked from commit eb07c341123fd85843c56ded82bd1e323fc660cb)
Signed-off-by: Rémi Duraffort <ivoire@videolan.org>