Keyframe Color Consistency Challenge Video Exemplar-Based Colorization Methods

[Dan64]

Hi NASS,

   there is already a post in this forum regarding this topic opened by me: Using Stable Diffision models for Colorization

   I confirm that currently Qwen-Image-Edit is the best model for colorize B&W images. 
   I tried all the models available, including Fire-Image-Edit, but  Qwen-Image-Edit is much, much better.

   Currently my pipeline to colorize movies is the following:

    1) extract the reference frames (with HAVC)
        

clip = havc.HAVC_read_video(source=VideoPath)
clip = havc.HAVC_extract_reference_frames(clip, sc_threshold=0.035, sc_tht_ssim=0.8, sc_tht_offset=2, sc_min_int=20, sc_min_freq=15, sc_tht_white=0.70, sc_tht_black=0.09, sc_framedir=RefDir, sc_algo=1, ref_ext="jpg", ref_jpg_quality=95, ref_override=False, sc_debug=False)
# adjusting output color from RGB24 to YUV420P10 for x265Model
clip = core.resize.Bicubic(clip=clip, format=vs.YUV420P10, matrix_s="709", range_in_s="full", range_s="limited")

    2) colorize the reference frames with a DiT model (currently I'm using Nunchaku Qwen Image Edit 2511) 

prompt = "Colorize this image, natural colors. Strictly preserve all shapes, edges and background details."

   
    3) propagate the color of reference frames to full clip (with HAVC)

clip = havc.HAVC_read_video(source=VideoPath)
# adding colors using HAVC
clip = havc.HAVC_cmnet2(clip, method=4, sc_framedir=RefDir, encode_mode=0, render_speed="auto", max_memory_frames=50, ref_mode=0, render_vivid=False)
# adjusting output color from RGB24 to YUV420P10 for x265Model
clip = core.resize.Bicubic(clip=clip, format=vs.YUV420P10, matrix_s="709", range_in_s="full", range_s="limited", dither_type="error_diffusion")

   The films colorized in this manner achieve a cinema-grade quality
   I hope this helps.

Dan

P.S.
The HAVC_cmnet2() function that I'm using, is the one available in the coming version of HAVC 5.8.0, the one currently available in HAVC 5.6.7 was a my previous attempt of introducing the sliding window memory in ColorMNet, but given the lack of permanent memory It was not working, the produced colors were faded.