ham_convert 1.6.1

New in this version: improved bayer and checks dithering, expanded command line mode.

Main mirror (all stable and testing versions)
External mirror


  • Dynamic Hires: recommended dithering propagation factor is now available as 0%.
  • Dynamic Hires: improved the following dithering modes – checks, bayer 2×2, bayer 4×4, bayer 8×8.
  • Amiga indexed modes: improved the following dithering modes – checks, bayer 2×2.
  • Fakemode: added 1×3 triple height, 3×1 normal and 3×1 triple width variants. 1×3 triple height variant after converting to 256-color AGA they can be used on Amiga.
  • Command line batch mode: txt file with a list of input files is now also accepted. Just replace full_image_path with bath_file_path. File extension must be txt.
  • Command line: new optional parameters: quant_wu option enables Wu’s color quantizer (usually faster than NeuQuant and often produces better results, enabled by default in non-ham modes), divesity_X (X values listed below), propagation_X (X values listed below).
  • Command line: added ham6_slowest (slowest conversion, best quality), ham6_fastest, ham6_ludicrous, ham8_fastest modes.
  • Updated command line mode info:
    java -Xmx4g -Xms1g -jar ham_convert.jar file_path mode optional_parameters (example: java -jar ham_convert.jar C:\img\test.png ham6 norle).
    If you start the program without “java -jar” it will be launched in the background.
    Ham6 and ham8 modes support multiple conversion profiles – normal which offers good best compromise between speed and quality, fast – faster but still producing decent picture quality, fastest – lower quality than and faster than fast, slow – best quality when speed is not important.

    • Parameter 1 – source file path (mandatory): jpg/png/gif image or txt file with one image path per line for bath conversion (unicode console required for diacritic characters).
    • Parameter 2 – mode (mandatory): ham6, ham6_slow, ham6_slowest, ham6_fast, ham6_fastest, ham6_ludicrous, ham8, ham8_fast, ham8_fastest, ham8_slow, ocs4, ocs8, ocs16, ocs32, ehb, aga64, aga128, aga256, dhires (dynamic hires 16-color per line).
      Program will be terminated if mode parameter is missing/incorrect or any of the other parameters is incorrect.
    • Parameter 3+ – optional settings:
      • dither (enable Bayer dithering for most modes, Checks for DynamicHires, Checks lines-mixed for ham6),
      • dither_fs (enable Floyd-Steinberg dithering for most modes, Constrained Sierra Lite for DynamicHires, adds additional noise to ham6 that can increase the number of artefacts),
      • norle (disable lossless iff rle compression),
      • normalize (stretch contrast – normalize range to 0-255),
      • black_bkd (force black background color – always set palette color 0 to black),
      • fixed_pal (use fixed palette: 16-level grayscale on ocs, rgb453level+6level grayscale on aga),
      • quant_wu (use Wu’s color quantizer instead of NeuQuant),
      • diversity_X (similar color removal strength, X=0-6 for ehb, X=0-9 for other modes, not supported in ham8 and dhires),
      • propagation_X (error propagation factor, requires dither_fs, X=0-100).
  • Command line ham6 conversion profiles (from highest to lowest quality):
    • ham6_slowest (ham6 with slower palette optimizer),
    • ham6_slow (ham6 with normal palette optimizer),
    • ham6 (same as default gui settings, optimal speed/quality),
    • ham6_fast (decent quality),
    • ham6_fastest,
    • ham6_ludicrous.
  • Command line ham8 conversion profiles (from highest to lowest quality):
    • ham8_slow,
    • ham8 (same as default gui settings, optimal speed/quality),
    • ham8_fast (decent quality),
    • ham8_fastest,

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