PNG: Types

WARNING

• PNG is pre-v1.0.0, and the public API should be expected to change between releases.
  Not all features defined in the PNG 3.0 specification are currently supported, and certain PNG data may fail or partially fail to decode. (for more information, see PNG: Decoding, Compatibility)

General Types

ColorSpace

"truecolor" | "grayscale" | "indexed"

A string literal specifying the color type of an image.

---

Chunk

Equivalent to CriticalChunk | AncillaryChunk.

CriticalChunk

| "IHDR" | "PLTE" | "IDAT" | "IEND"

AncillaryChunk

| "tRNS" | "cHRM" | "gAMA" | "iCCP"
| "sBIT" | "sRGB" | "cICP" | "mDCV"
| "cLLI" | "tEXt" | "zTXt" | "iTXt"
| "bKGD" | "pHYs" | "sPLT" | "eXIf"
| "tIME" | "acTL" | "fcTL" | "fdAT"

Decode Types

Parsed

{
	width: number,
	height: number,
	frames: number,
	alpha: boolean,

	headers: {
		interlacing: boolean,
		channels: number,
		bit_depth: number,
		color_space: types.ColorSpace,
	},
	palette: {number}?,

	cel: (frame: number?, target: ColorTarget?) -> (Cel?, CelError),
}

Property	Description
headers	Image information obtained from the IHDR chunk.
palette	Array of packed RGBA8 colors assigned to palette indexes (1-indexed). nil if image has no PLTE chunk.
...	(see Parsed)

PNG-specific extension of Parsed.

---

DecodeOptions

{
	crc: ("all" | "critical" | "none")?,
}

Property	Description
crc	String literal specifying which chunk checksums are validated.

PNG-specific decode options accepted by decode().

---

DecodeError

Equivalent to Error<DecodeErrorCode>.

DecodeErrorCode

| "unsupported"
| "overflow"
| "unexpected_eof"
| "invalid_signature"
| "invalid_crc"
| "invalid_length"
| "invalid_header"
| "unknown_chunk"
| "missing_chunk"

---

CelError

Equivalent to Error<CelErrorCode>.

CelErrorCode

| "unsupported"
| "invalid_header"
| "invalid_filter"
| "invalid_option"

---

Encode Types

(TBD)