can1357
975c836015
- Replaced baked module-load value with per-call `isWebPExcluded()` so runtime env changes take effect. - Only `"1"` and `"true"` (case-insensitive) enable exclusion; empty string and `"0"` are treated as disabled. - Fast path now bypassed for WebP sources when exclusion is active. - Explicit error surfaced when decode fails and WebP exclusion cannot be honored.
310 lines
9.6 KiB
TypeScript
310 lines
9.6 KiB
TypeScript
import type { ImageContent } from "@oh-my-pi/pi-ai";
|
||
|
||
export interface ImageResizeOptions {
|
||
maxWidth?: number;
|
||
maxHeight?: number;
|
||
maxBytes?: number;
|
||
jpegQuality?: number;
|
||
excludeWebP?: boolean;
|
||
}
|
||
|
||
export interface ResizedImage {
|
||
buffer: Uint8Array;
|
||
mimeType: string;
|
||
originalWidth: number;
|
||
originalHeight: number;
|
||
width: number;
|
||
height: number;
|
||
wasResized: boolean;
|
||
get data(): string;
|
||
}
|
||
|
||
// 500KB target — aggressive compression; Anthropic's 5MB per-image cap is rarely the
|
||
// binding constraint once images are downsized to 1568px (Anthropic's internal threshold).
|
||
const DEFAULT_MAX_BYTES = 500 * 1024;
|
||
|
||
const DEFAULT_OPTIONS: Required<Omit<ImageResizeOptions, "excludeWebP">> = {
|
||
// Anthropic's "internal recommended size" — Claude internally caps images at
|
||
// 1568px on the longest edge before vision processing.
|
||
maxWidth: 1568,
|
||
maxHeight: 1568,
|
||
maxBytes: DEFAULT_MAX_BYTES,
|
||
jpegQuality: 80,
|
||
};
|
||
|
||
/**
|
||
* Read `OMP_NO_WEBP` per-call so runtime toggles take effect.
|
||
* Only `"1"` and `"true"` (case-insensitive) enable exclusion — an empty string
|
||
* or `"0"` MUST be treated as disabled.
|
||
*/
|
||
function isWebPExcluded(): boolean {
|
||
const raw = Bun.env.OMP_NO_WEBP;
|
||
if (raw === undefined) return false;
|
||
const v = raw.toLowerCase();
|
||
return v === "1" || v === "true";
|
||
}
|
||
|
||
/** Pick the smallest of N encoded buffers. */
|
||
function pickSmallest(...candidates: Array<{ buffer: Uint8Array; mimeType: string }>): {
|
||
buffer: Uint8Array;
|
||
mimeType: string;
|
||
} {
|
||
return candidates.reduce((best, c) => (c.buffer.length < best.buffer.length ? c : best));
|
||
}
|
||
|
||
/** Polyfill for Buffer.toBase64, technically since it derives from Uint8Array it should exist but Bun reasons... */
|
||
Buffer.prototype.toBase64 = function (this: Buffer) {
|
||
return new Uint8Array(this.buffer, this.byteOffset, this.byteLength).toBase64();
|
||
};
|
||
|
||
/**
|
||
* Resize and recompress an image to fit within the specified max dimensions and file size.
|
||
*
|
||
* Strategy:
|
||
* 1. Probe metadata. If already within all limits, return original.
|
||
* 2. Resize to fit max dimensions and encode at high quality across PNG/JPEG (+ WebP) — return smallest.
|
||
* 3. If still too large, walk a lossy JPEG/WebP quality ladder.
|
||
* 4. If still too large, walk a dimension-scale ladder × quality ladder.
|
||
* 5. If still too large, return the smallest variant produced.
|
||
*
|
||
* Set OMP_NO_WEBP to exclude WebP from encoding (llama.cpp STB doesn't decode it).
|
||
*
|
||
* Backed by `Bun.Image`: a chainable native pipeline that runs decode/transform/encode
|
||
* off the JS thread when the terminal (`.bytes()`) is awaited.
|
||
*/
|
||
export async function resizeImage(img: ImageContent, options?: ImageResizeOptions): Promise<ResizedImage> {
|
||
const excludeWebP = options?.excludeWebP ?? isWebPExcluded();
|
||
const opts = { ...DEFAULT_OPTIONS, ...options, excludeWebP };
|
||
const inputBuffer = Buffer.from(img.data, "base64");
|
||
|
||
try {
|
||
const { width: originalWidth, height: originalHeight, format } = await new Bun.Image(inputBuffer).metadata();
|
||
const sourceMime = img.mimeType ?? `image/${format}`;
|
||
|
||
// Fast path: already within dimensions AND well under budget.
|
||
// Threshold is 1/4 of budget — if already that compact, don't re-encode.
|
||
// Avoids wasted work on tiny icons/diagrams while ensuring larger PNGs
|
||
// still get JPEG-compressed.
|
||
const originalSize = inputBuffer.length;
|
||
const comfortableSize = opts.maxBytes / 4;
|
||
if (
|
||
originalWidth <= opts.maxWidth &&
|
||
originalHeight <= opts.maxHeight &&
|
||
originalSize <= comfortableSize &&
|
||
!(opts.excludeWebP && sourceMime === "image/webp")
|
||
) {
|
||
return {
|
||
buffer: inputBuffer,
|
||
mimeType: sourceMime,
|
||
originalWidth,
|
||
originalHeight,
|
||
width: originalWidth,
|
||
height: originalHeight,
|
||
wasResized: false,
|
||
get data() {
|
||
return img.data;
|
||
},
|
||
};
|
||
}
|
||
|
||
// Calculate initial dimensions respecting max limits
|
||
let targetWidth = originalWidth;
|
||
let targetHeight = originalHeight;
|
||
|
||
if (targetWidth > opts.maxWidth) {
|
||
targetHeight = Math.round((targetHeight * opts.maxWidth) / targetWidth);
|
||
targetWidth = opts.maxWidth;
|
||
}
|
||
if (targetHeight > opts.maxHeight) {
|
||
targetWidth = Math.round((targetWidth * opts.maxHeight) / targetHeight);
|
||
targetHeight = opts.maxHeight;
|
||
}
|
||
|
||
// First-attempt encoder: try PNG and JPEG (+ WebP if not excluded) — return smallest.
|
||
// PNG wins for line art / few-color UI; JPEG wins for photographic content;
|
||
// WebP usually beats JPEG by 25–35% but is disabled when OMP_NO_WEBP is set
|
||
// because many local inference backends (llama.cpp STB) don't decode it.
|
||
async function encodeSmallest(
|
||
width: number,
|
||
height: number,
|
||
quality: number,
|
||
): Promise<{ buffer: Uint8Array; mimeType: string }> {
|
||
const candidates = await Promise.all([
|
||
new Bun.Image(inputBuffer)
|
||
.resize(width, height)
|
||
.png()
|
||
.bytes()
|
||
.then(b => ({ buffer: b, mimeType: "image/png" })),
|
||
new Bun.Image(inputBuffer)
|
||
.resize(width, height)
|
||
.jpeg({ quality })
|
||
.bytes()
|
||
.then(b => ({ buffer: b, mimeType: "image/jpeg" })),
|
||
...(opts.excludeWebP
|
||
? []
|
||
: [
|
||
new Bun.Image(inputBuffer)
|
||
.resize(width, height)
|
||
.webp({ quality })
|
||
.bytes()
|
||
.then(b => ({ buffer: b, mimeType: "image/webp" })),
|
||
]),
|
||
]);
|
||
return pickSmallest(...candidates);
|
||
}
|
||
|
||
// Lossy encoder for quality/dimension fallback ladders. PNG is excluded since
|
||
// it's lossless and doesn't respond to quality parameters. WebP is included
|
||
// unless OMP_NO_WEBP is set (llama.cpp STB incompatibility).
|
||
async function encodeLossy(
|
||
width: number,
|
||
height: number,
|
||
quality: number,
|
||
): Promise<{ buffer: Uint8Array; mimeType: string }> {
|
||
const candidates = await Promise.all([
|
||
new Bun.Image(inputBuffer)
|
||
.resize(width, height)
|
||
.jpeg({ quality })
|
||
.bytes()
|
||
.then(b => ({ buffer: b, mimeType: "image/jpeg" })),
|
||
...(opts.excludeWebP
|
||
? []
|
||
: [
|
||
new Bun.Image(inputBuffer)
|
||
.resize(width, height)
|
||
.webp({ quality })
|
||
.bytes()
|
||
.then(b => ({ buffer: b, mimeType: "image/webp" })),
|
||
]),
|
||
]);
|
||
return pickSmallest(...candidates);
|
||
}
|
||
// Quality ladder — more aggressive steps for tighter budgets
|
||
const qualitySteps = [70, 60, 50, 40];
|
||
const scaleSteps = [1.0, 0.75, 0.5, 0.35, 0.25];
|
||
|
||
let best: { buffer: Uint8Array; mimeType: string };
|
||
let finalWidth = targetWidth;
|
||
let finalHeight = targetHeight;
|
||
|
||
// First attempt: resize to target, try PNG/JPEG (+ WebP), pick smallest
|
||
best = await encodeSmallest(targetWidth, targetHeight, opts.jpegQuality);
|
||
|
||
if (best.buffer.length <= opts.maxBytes) {
|
||
return {
|
||
buffer: best.buffer,
|
||
mimeType: best.mimeType,
|
||
originalWidth,
|
||
originalHeight,
|
||
width: finalWidth,
|
||
height: finalHeight,
|
||
wasResized: true,
|
||
get data() {
|
||
return Buffer.from(best.buffer).toBase64();
|
||
},
|
||
};
|
||
}
|
||
|
||
// Still too large — lossy JPEG (+ WebP) ladder with decreasing quality
|
||
for (const quality of qualitySteps) {
|
||
best = await encodeLossy(targetWidth, targetHeight, quality);
|
||
|
||
if (best.buffer.length <= opts.maxBytes) {
|
||
return {
|
||
buffer: best.buffer,
|
||
mimeType: best.mimeType,
|
||
originalWidth,
|
||
originalHeight,
|
||
width: finalWidth,
|
||
height: finalHeight,
|
||
wasResized: true,
|
||
get data() {
|
||
return Buffer.from(best.buffer).toBase64();
|
||
},
|
||
};
|
||
}
|
||
}
|
||
|
||
// Still too large — reduce dimensions progressively with the lossy ladder
|
||
for (const scale of scaleSteps) {
|
||
finalWidth = Math.round(targetWidth * scale);
|
||
finalHeight = Math.round(targetHeight * scale);
|
||
|
||
if (finalWidth < 100 || finalHeight < 100) {
|
||
break;
|
||
}
|
||
|
||
for (const quality of qualitySteps) {
|
||
best = await encodeLossy(finalWidth, finalHeight, quality);
|
||
|
||
if (best.buffer.length <= opts.maxBytes) {
|
||
return {
|
||
buffer: best.buffer,
|
||
mimeType: best.mimeType,
|
||
originalWidth,
|
||
originalHeight,
|
||
width: finalWidth,
|
||
height: finalHeight,
|
||
wasResized: true,
|
||
get data() {
|
||
return Buffer.from(best.buffer).toBase64();
|
||
},
|
||
};
|
||
}
|
||
}
|
||
}
|
||
|
||
// Last resort: return smallest version we produced
|
||
return {
|
||
buffer: best.buffer,
|
||
mimeType: best.mimeType,
|
||
originalWidth,
|
||
originalHeight,
|
||
width: finalWidth,
|
||
height: finalHeight,
|
||
wasResized: true,
|
||
get data() {
|
||
return Buffer.from(best.buffer).toBase64();
|
||
},
|
||
};
|
||
} catch {
|
||
// Bun.Image rejected the input — we cannot decode/re-encode it.
|
||
// When the caller demanded WebP exclusion AND the original is WebP,
|
||
// returning the original buffer would silently violate that contract,
|
||
// so surface an explicit error instead.
|
||
if (excludeWebP && (img.mimeType === "image/webp" || !img.mimeType)) {
|
||
throw new Error("resizeImage: failed to decode image and cannot honor excludeWebP for a WebP source");
|
||
}
|
||
return {
|
||
buffer: inputBuffer,
|
||
mimeType: img.mimeType,
|
||
originalWidth: 0,
|
||
originalHeight: 0,
|
||
width: 0,
|
||
height: 0,
|
||
wasResized: false,
|
||
get data() {
|
||
return img.data;
|
||
},
|
||
};
|
||
}
|
||
}
|
||
|
||
/**
|
||
* Format a dimension note for resized images.
|
||
* This helps the model understand the coordinate mapping.
|
||
*/
|
||
export function formatDimensionNote(result: ResizedImage): string | undefined {
|
||
if (!result.wasResized) {
|
||
return undefined;
|
||
}
|
||
if (!result.originalWidth || !result.originalHeight || !result.width || !result.height) {
|
||
return undefined;
|
||
}
|
||
if (result.width === result.originalWidth && result.height === result.originalHeight) {
|
||
return undefined;
|
||
}
|
||
const scale = result.originalWidth / result.width;
|
||
return `[Image: original ${result.originalWidth}x${result.originalHeight}, displayed at ${result.width}x${result.height}. Multiply coordinates by ${scale.toFixed(2)} to map to original image.]`;
|
||
}
|