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• lavc : Drop deprecated emu edge functionality

  5 décembre 2016, par Vittorio Giovara

  lavc : Drop deprecated emu edge functionality
  Deprecated in 01/2014.
  

  • [DBH] libavcodec/avcodec.h
  • [DBH] libavcodec/options_table.h
  • [DBH] libavcodec/utils.c
  • [DBH] libavcodec/version.h

• how to improve edge interpolation of rotation in moviepy

  15 juillet 2021, par OneWorld

  I tried changing the interpolation method of rotation from 'bilinear' to 'bicubic' in the below, but it didn't seem to improve the edge interpolation. (it still looks a little bit jagged)

  


  I was wondering what I need to do to improve this ?

  


  import moviepy.editor as mped
import sys
import numpy as np

bgrd_width = 200
bgrd_height = 200
sunset = mped.ImageClip("sunset200x100.jpg", duration=1).set_position((1, 1))
bgrd = mped.ColorClip(size=(bgrd_width, bgrd_height), color=np.array([200, 200, 200]).astype(np.uint8), duration=3).set_position((0, 0))

angle = 56
interpolation = 'bicubic'

rotated_sunset = sunset.add_mask().rotate(angle, unit='deg', expand=True, resample=interpolation).set_duration(3)
stacked_clips = mped.CompositeVideoClip([bgrd, rotated_sunset], size=[bgrd_width, bgrd_height])

stacked_clips.write_videofile(f'sunset_rotated_{angle}_{interpolation}.mp4', fps=5)



  


  See attached comparison image of bilinear and bicubic interpolation.


  


  Adding to this, I have seen now that the inside of the image does improve in quality with cubic, compared with nearest neighbour.

  


  

  


  The reason for the smooth inside, and jagged asset edge is because there's no pixel to sample from outside the boundary of the image, when interpolation is applied.

  


  I wrote some moviepy code, which adds a black margin (which actually turns transparent) and mask and then rotates. With bicubic interpolation it creates course, black lines, with a strange blend. However, with bilinear interpolation, the lines are much less apparent.

  


  # Add margin, add mask, rotate with interpolation of transparent 2 pixel border.
original_clip = mped.ImageClip("sunset200x100.jpg")
opaque_color = np.array([255, 255, 255]).astype(np.uint8)
margin_color = np.array([0, 0, 0]).astype(np.uint8)
margin_added_clip = original_clip.margin(2, color=margin_color)  # adds 2 pixel black border.
color_mask = mped.ColorClip(size=(original_clip.size), color=opaque_color).margin(2, color=margin_color)
mask = color_mask.to_mask()  # converts to grayscale with values between 0 and 1
masked_clip = margin_added_clip.set_mask(mask)  # adds the float mask to the clip
rotated_sunset = masked_clip.rotate(56, unit='deg', expand=True, resample="bicubic")
rotated_sunset.save_frame("sunset_rotated_56_degrees_moviepy_with_2px_mask.png")  # uses imageio to save the frame.


  


  

  


  However,

  


  If you switch from bicubic to bilinear, it looks a lot better :-

  


  

  


• hevcdsp : separated sao edge filter and pixel restore funcs

  4 février 2015, par Seppo Tomperi

  hevcdsp : separated sao edge filter and pixel restore funcs
  Reviewed-by : Michael Niedermayer <michaelni@gmx.at>
  
  Reviewed-by : Christophe Gisquet <christophe.gisquet@gmail.com>
  
  Reviewed-by : Mickaël Raulet <mraulet@insa-rennes.fr>
  

  • [DH] libavcodec/hevc_filter.c
  • [DH] libavcodec/hevcdsp.c
  • [DH] libavcodec/hevcdsp.h
  • [DH] libavcodec/hevcdsp_template.c