methods.json

{
  "global": {
    "crop": {
      "type": [
        "number",
        "number",
        "number",
        "number"
      ],
      "description": "crop picture with the given rectangle"
    },
    "multiThreading": {
      "key": "mt",
      "type": "boolean",
      "description": "use multi-threading if available"
    },
    "noasm": {
      "type": "boolean",
      "description": "disable all assembly optimizations"
    }
  },
  "cwebp": {
    "quality": {
      "key": "q",
      "type": "number",
      "description": "quality factor (0:small..100:big), default=75"
    },
    "alphaQuality": {
      "key": "alpha_q",
      "type": "number",
      "description": "transparency-compression quality (0..100), default=100"
    },
    "preset": {
      "description": "preset setting, one of: default, photo, picture, drawing, icon, text"
    },
    "losslessPreset": {
      "key": "z",
      "type": "number",
      "description": "activates lossless preset with given level in [0:fast, ..., 9:slowest]"
    },
    "compression": {
      "key": "m",
      "type": "number",
      "description": "compression method (0=fast, 6=slowest), default=4"
    },
    "segments": {
      "type": "number",
      "description": "number of segments to use (1..4), default=4"
    },
    "size": {
      "type": "number",
      "description": "target size (in bytes)"
    },
    "psnr": {
      "type": "number",
      "description": "target PSNR (in dB. typically: 42)"
    },
    "inputSize": {
      "key": "s",
      "type": [
        "number",
        "number"
      ],
      "description": "input size (width x height) for YUV"
    },
    "sns": {
      "type": "number",
      "description": "spatial Noise Shaping (0:off, 100:max), default=50"
    },
    "strength": {
      "key": "f",
      "type": "number",
      "description": "filter strength (0=off..100), default=60"
    },
    "sharpness": {
      "type": "number",
      "description": "filter sharpness (0:most .. 7:least sharp), default=0"
    },
    "strong": {
      "type": "boolean",
      "exclude": "nostrong",
      "description": "use strong filter instead of simple (default)"
    },
    "nostrong": {
      "type": "boolean",
      "exclude": "strong",
      "aliases": [
        "simple"
      ],
      "description": "use simple filter instead of strong"
    },
    "sharpYUV": {
      "key": "sharp_yuv",
      "type": "boolean",
      "description": "use sharper (and slower) RGB->YUV conversion"
    },
    "partitionLimit": {
      "key": "partition_limit",
      "type": "number",
      "description": "limit quality to fit the 512k limit on the first partition (0=no degradation ... 100=full)"
    },
    "pass": {
      "type": "number",
      "description": "analysis pass number (1..10)"
    },
    "resize": {
      "type": [
        "number",
        "number"
      ],
      "description": "resize picture (after any cropping)"
    },
    "lowMemory": {
      "key": "low_memory",
      "type": "boolean",
      "description": "reduce memory usage (slower encoding)"
    },
    "dump": {
      "key": "d",
      "description": "dump the compressed output (PGM file)"
    },
    "alphaMethod": {
      "key": "alpha_method",
      "type": "number",
      "description": "transparency-compression method (0..1), default=1"
    },
    "alphaFilter": {
      "key": "alpha_filter",
      "description": "predictive filtering for alpha plane, one of: none, fast (default) or best"
    },
    "alphaCleanup": {
      "key": "alpha_cleanup",
      "type": "boolean",
      "description": "clean RGB values in transparent area"
    },
    "blendAlpha": {
      "key": "blend_alpha",
      "description": "blend colors against background color expressed as RGB values written in hexadecimal, e.g. 0xc0e0d0 for red=0xc0 green=0xe0 and blue=0xd0"
    },
    "noalpha": {
      "type": "boolean",
      "description": "discard any transparency information"
    },
    "exact": {
      "type": "boolean",
      "description": "preserve RGB values in transparent area, default=off"
    },
    "lossless": {
      "type": "boolean",
      "description": "encode image losslessly, default=off"
    },
    "nearLossless": {
      "key": "near_lossless",
      "type": "number",
      "description": "use near-lossless image preprocessing (0..100=off), default=100"
    },
    "hint": {
      "description": "specify image characteristics hint, one of: photo, picture or graph"
    },
    "metadata": {
      "description": "comma separated list of metadata to copy from the input to the output if present, valid values: all, none (default), exif, icc, xmp"
    },
    "jpegLike": {
      "key": "jpeg_like",
      "type": "boolean",
      "description": "roughly match expected JPEG size (experimental)"
    },
    "autoAdjust": {
      "key": "af",
      "type": "boolean",
      "description": "auto-adjust filter strength (experimental)"
    },
    "pre": {
      "type": "number",
      "description": "pre-processing filter (experimental)"
    },
    "verbose": {
      "key": "v",
      "type": "boolean",
      "description": "verbose error reporting"
    }
  },
  "dwebp": {
    "png": {
      "key": "-",
      "type": "boolean",
      "exclude": ["pam", "ppm", "bmp", "tiff", "pgm", "yuv"],
      "description": "save as PNG format (default)"
    },
    "pam": {
      "type": "boolean",
      "exclude": ["png", "ppm", "bmp", "tiff", "pgm", "yuv"],
      "description": "save the raw RGBA samples as a color PAM"
    },
    "ppm": {
      "type": "boolean",
      "exclude": ["png", "pam", "bmp", "tiff", "pgm", "yuv"],
      "description": "save the raw RGB samples as a color PPM"
    },
    "bmp": {
      "type": "boolean",
      "exclude": ["png", "pam", "ppm", "tiff", "pgm", "yuv"],
      "description": "save as uncompressed BMP format"
    },
    "tiff": {
      "type": "boolean",
      "exclude": ["png", "pam", "ppm", "bmp", "pgm", "yuv"],
      "description": "save as uncompressed TIFF format"
    },
    "pgm": {
      "type": "boolean",
      "exclude": ["png", "pam", "ppm", "bmp", "tiff", "yuv"],
      "description": "save the raw YUV samples as a grayscale PGM file with IMC4 layout"
    },
    "yuv": {
      "type": "boolean",
      "exclude": ["png", "pam", "ppm", "bmp", "tiff", "pgm"],
      "description": "save the raw YUV samples in flat layout"
    },
    "dither": {
      "type": "number",
      "description": "dithering strength (in 0..100)"
    },
    "alphaDither": {
      "key": "alpha_dither",
      "type": "boolean",
      "description": "use alpha-plane dithering if needed"
    },
    "scale": {
      "type": [
        "number",
        "number"
      ],
      "aliases": [
        "resize"
      ],
      "description": "scale the output (after any cropping)"
    },
    "flip": {
      "type": "boolean",
      "description": "flip the output vertically"
    },
    "nofancy": {
      "type": "boolean",
      "description": "don't use the fancy YUV420 upscaler."
    },
    "nofilter": {
      "type": "boolean",
      "description": "disable in-loop filtering."
    },
    "nodither": {
      "type": "boolean",
      "description": "disable dithering"
    },
    "alpha": {
      "type": "boolean",
      "description": "only save the alpha plane."
    },
    "incremental": {
      "type": "boolean",
      "description": "use incremental decoding (useful for tests)"
    }
  }
}