kiteimage/io.github.yuroyami.kiteimage/KiteImage

KiteImage

The KiteImage facade. Everything is pure computation on byte arrays: no I/O, no threads, no platform types: so it behaves identically on every KMP target.

val bitmap = KiteImage.decode(bytes)          // sniffs the format, dispatches
val anim = KiteImage.decodeAnimation(bytes)   // frames + delays + loop count
val format = KiteImage.detect(bytes)          // just the sniff
val info = KiteImage.probe(bytes)             // size + depth + frames, no decode

Functions

decode

fun decode(data: ByteArray, applyOrientation: Boolean = false): KiteBitmap

Decode data into a KiteBitmap, sniffing the format first. Animated inputs yield their first frame (composited); use decodeAnimation for the full sequence.

decodeAnimation

fun decodeAnimation(data: ByteArray, applyOrientation: Boolean = false, cancellationCheck: () -> Unit? = null): KiteAnimation

Decode data as an animation. GIF returns every composited frame with delays and the loop count; static formats return a single zero-delay frame, so this is safe to call on anything decode accepts.

detect

fun detect(data: ByteArray): ImageFormat?

Identify data's format from its magic bytes, or null if unrecognised.

encodeBmp

fun encodeBmp(bitmap: KiteBitmap): ByteArray

Encode bitmap as a BMP: 24-bit BI_RGB when it is opaque, or 32-bit BI_BITFIELDS under a V4 header when it carries alpha (plain 32-bit BMP alpha is officially "reserved", and half the world's readers discard it). Uncompressed and lossless either way.

encodeGif

fun encodeGif(animation: KiteAnimation, dither: Boolean = true): ByteArray

Encode animation as an animated GIF89a: one shared colour table, per-frame delays, and the NETSCAPE2.0 loop count. Frames must all be canvas-sized, which is exactly what decodeAnimation produces.

fun encodeGif(bitmap: KiteBitmap, dither: Boolean = true): ByteArray

Encode bitmap as a GIF89a. Colours are quantised to the format's 256-entry limit; images that already fit encode losslessly. Alpha is reduced to GIF's single transparent index at a 50% threshold.

encodeJpeg

fun encodeJpeg(bitmap: KiteBitmap, quality: Int = 90): ByteArray

Encode bitmap as a baseline JPEG at quality 1..100 (default 90). Alpha is discarded (JPEG has none); quality ≤ 90 uses 4:2:0 chroma subsampling, above that 4:4:4; stb_image_write's behavior.

encodePng

fun encodePng(bitmap: KiteBitmap): ByteArray

Encode bitmap as a PNG: 8-bit RGB, or RGBA when any pixel carries alpha. Lossless: decoding the result returns the exact same pixels.

probe

fun probe(data: ByteArray): ImageInfo

Read data's header and report what it says: dimensions, bit depth, declared alpha, animation frame count, EXIF orientation, and whether this build can decode it. No pixels are decoded and no image-sized buffer is allocated, so this stays cheap on a 50 MP file.

probeOrNull

fun probeOrNull(data: ByteArray): ImageInfo?

probe, but null instead of throwing on unrecognised or malformed input.