Image codec primitives for MoonBit with PNG/BMP/JPEG decode+encode, GIF/WebP/ICO/AVIF encode, and resize.

moonbit

image

bmp

jpeg

gif

png

webp

ico

avif

encoder

decoder

moon add mizchi/image@0.4.3

Download zip

Author

mizchi

Version

0.4.3

License

Apache-2.0

Repository

github.com/mizchi/image-mbt

Last updated

26 days ago

Downloads

15K

Dependencies

mizchi/zlib0.4.8

README

#mizchi/image

Image codec primitives for MoonBit. Core codecs have no external dependencies except mizchi/zlib; the AVIF js-target MVP uses browser AVIF canvas support or local ffmpeg.

#Features

PNG decode / encode (RGBA8, adaptive row filtering)
BMP decode / encode
JPEG baseline decode / encode
GIF encode (single-frame, indexed palette, binary transparency)
WebP lossless encode (still image)
ICO encode (single-image, PNG payload)
AVIF encode (js target MVP, opaque still image)
Resize with Nearest / Bilinear / Bicubic interpolation

All decoded images are normalized to ImageData (RGBA8 buffer).

#Install

moon add mizchi/image

#Usage

// PNG decode → resize → encode
let img = @image.decode_png(png_bytes)
let resized = @image.resize(img, 128, 128, Bilinear)
let out = @image.encode_png(resized)

// JPEG encode (quality defaults to 85)
let jpg = @image.encode_jpeg(resized)

// GIF encode (<= 256 colors, alpha 0/255 only)
let gif = @image.encode_gif(resized)

// WebP lossless encode
let webp = @image.encode_webp(resized)

// ICO encode (single PNG-backed icon, <= 256x256)
let ico = @image.encode_ico(resized)

// AVIF encode (js target MVP, opaque images only)
let avif = @image.encode_avif(resized)

// Stream decode (PNG/BMP auto detect)
let rows : Array[Bytes] = []
let info = @image.decode_image_stream(
  image_bytes,
  on_row=fn(_y, row) { rows.push(row) },
)
inspect((info.format, info.width, info.height))

#API

pub fn decode_png(Bytes) -> ImageData raise DecodeError
pub fn decode_png_stream(Bytes, on_row~ : (Int, Bytes) -> Unit) -> IhdrData raise DecodeError
pub fn decode_image_stream(Bytes, on_row~ : (Int, Bytes) -> Unit) -> StreamImageInfo raise DecodeError
pub fn encode_png(ImageData) -> Bytes raise EncodeError
pub fn decode_bmp(Bytes) -> ImageData raise DecodeError
pub fn decode_bmp_stream(Bytes, on_row~ : (Int, Bytes) -> Unit) -> (Int, Int) raise DecodeError
pub fn encode_bmp(ImageData) -> Bytes raise EncodeError
pub fn decode_jpeg(Bytes) -> ImageData raise DecodeError
pub fn encode_jpeg(ImageData, quality? : Int = 85) -> Bytes raise EncodeError
pub fn encode_gif(ImageData) -> Bytes raise EncodeError
pub fn encode_webp(ImageData) -> Bytes raise EncodeError
pub fn encode_ico(ImageData) -> Bytes raise EncodeError
pub fn encode_avif(ImageData) -> Bytes raise EncodeError
pub fn resize(ImageData, Int, Int, ResizeMethod) -> ImageData raise EncodeError

#Types

pub(all) struct ImageData { width : Int; height : Int; data : Bytes }
pub(all) enum ResizeMethod { Nearest; Bilinear; Bicubic }

#Support

Feature	Decode	Encode	Targets	Notes
PNG	yes	yes	js / native / wasm-gc	RGBA8 normalize, stream decode
BMP	yes	yes	js / native / wasm-gc	decode: 24/32-bit, encode: 32-bit BGRA
JPEG	yes	yes	js / native / wasm-gc	baseline only
GIF	no	yes	js / native / wasm-gc	single-frame, <=256 colors, alpha 0/255 only
WebP	no	yes	js / native / wasm-gc	lossless still-image encoder
ICO	no	yes	js / native / wasm-gc	single PNG payload, <=256x256
AVIF	no	yes	js	opaque images only, requires browser AVIF canvas support or local ffmpeg
Resize	n/a	n/a	js / native / wasm-gc	Nearest / Bilinear / Bicubic

#License

Apache-2.0

#
DecodeError

source

pub(all) suberror DecodeError {
  InvalidSignature(String)
  InvalidChunkCrc(String)
  MissingChunk(String)
  UnsupportedFeature(String)
  CorruptData(String)
}

impl Show for DecodeError

#
EncodeError

source

pub(all) suberror EncodeError {
  InvalidDimensions(String)
  InvalidData(String)
}

impl Show for EncodeError

#
ColorType

source

pub enum ColorType {
  Grayscale
  Rgb
  Indexed
  GrayscaleAlpha
  Rgba
} derive(Eq, @moonbitlang/core/debug.Debug
Debug)

impl Show for ColorType

#
IhdrData

source

pub(all) struct IhdrData {
  width : Int
  height : Int
  bit_depth : Int
  color_type : ColorType
  compression : Int
  filter : Int
  interlace : Int
} derive(Eq)

impl Show for IhdrData

#
ImageData

source

pub(all) struct ImageData {
  width : Int
  height : Int
  data : Bytes
} derive(Eq, @moonbitlang/core/debug.Debug
Debug)

impl Show for ImageData

#
ImageFormat

source

pub(all) enum ImageFormat {
  Png
  Bmp
} derive(Eq, @moonbitlang/core/debug.Debug
Debug)

impl Show for ImageFormat

#
ResizeMethod

source

pub(all) enum ResizeMethod {
  Nearest
  Bilinear
  Bicubic
} derive(Eq)

impl Show for ResizeMethod

#
StreamImageInfo

source

pub(all) struct StreamImageInfo {
  format : ImageFormat
  width : Int
  height : Int
} derive(Eq)

impl Show for StreamImageInfo

#
decode_bmp

source

fn decode_bmp(raw : Bytes) -> ImageData raise DecodeError

#
decode_bmp_stream

source

fn decode_bmp_stream(raw : Bytes, on_row~ : (Int, Bytes) -> Unit) -> (Int, Int) raise DecodeError

#
decode_image_stream

source

fn decode_image_stream(raw : Bytes, on_row~ : (Int, Bytes) -> Unit) -> StreamImageInfo raise DecodeError

#
decode_jpeg

source

fn decode_jpeg(data : Bytes) -> ImageData raise DecodeError

#
decode_png

source

fn decode_png(raw : Bytes) -> ImageData raise DecodeError

#
decode_png_stream

source

fn decode_png_stream(raw : Bytes, on_row~ : (Int, Bytes) -> Unit) -> IhdrData raise DecodeError

#
encode_avif

source

fn encode_avif(_img : ImageData) -> Bytes raise EncodeError

#
encode_bmp

source

fn encode_bmp(img : ImageData) -> Bytes raise EncodeError

#
encode_gif

source

fn encode_gif(img : ImageData) -> Bytes raise EncodeError

#
encode_ico

source

fn encode_ico(img : ImageData) -> Bytes raise EncodeError

#
encode_jpeg

source

fn encode_jpeg(img : ImageData, quality? : Int) -> Bytes raise EncodeError

#
encode_png

source

fn encode_png(img : ImageData) -> Bytes raise EncodeError

#
encode_webp

source

fn encode_webp(img : ImageData) -> Bytes raise EncodeError

#
package_name

source

fn package_name() -> String

Project marker.

#
resize

source

fn resize(img : ImageData, new_width : Int, new_height : Int, resize_method : ResizeMethod) -> ImageData raise EncodeError

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image

#mizchi/image

#Features

#Install

#Usage

#API

#Types

#Support

#License

#DecodeError

#EncodeError

#ColorType

#IhdrData

#ImageData

#ImageFormat

#ResizeMethod

#StreamImageInfo

#decode_bmp

#decode_bmp_stream

#decode_image_stream

#decode_jpeg

#decode_png

#decode_png_stream

#encode_avif

#encode_bmp

#encode_gif

#encode_ico

#encode_jpeg

#encode_png

#encode_webp

#package_name

#resize

Source Files

#
DecodeError

#
EncodeError

#
ColorType

#
IhdrData

#
ImageData

#
ImageFormat

#
ResizeMethod

#
StreamImageInfo

#
decode_bmp

#
decode_bmp_stream

#
decode_image_stream

#
decode_jpeg

#
decode_png

#
decode_png_stream

#
encode_avif

#
encode_bmp

#
encode_gif

#
encode_ico

#
encode_jpeg

#
encode_png

#
encode_webp

#
package_name

#
resize