65 lines
1.9 KiB
JavaScript
65 lines
1.9 KiB
JavaScript
const sharp = require("sharp");
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const { spawnSync } = require("child_process");
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async function resizeAndMakeWhiteTransparent(inputPath, outputPath) {
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const whiteThreshold = 250; // treat >= as white
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const img = sharp(inputPath).ensureAlpha();
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// Get metadata to compute resize dimensions preserving aspect ratio
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const meta = await img.metadata();
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const origW = meta.width || 0;
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const origH = meta.height || 0;
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if (!origW || !origH) throw new Error("Unable to read image dimensions");
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const targetW = Math.max(origW, origH);
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const targetH = targetW;
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// Resize and output raw RGBA buffer
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const { data, info } = await img
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.resize(targetW, targetH, { fit: "fill" })
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.raw()
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.toBuffer({ resolveWithObject: true });
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const { width: w, height: h, channels } = info; // channels should be 4 (RGBA)
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if (channels < 3) throw new Error("Unexpected channel count");
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// Modify alpha for near-white pixels
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for (let i = 0; i < data.length; i += channels) {
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const r = data[i];
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const g = data[i + 1];
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const b = data[i + 2];
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const a = channels === 4 ? data[i + 3] : 255;
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if (
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a > 0 &&
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r >= whiteThreshold &&
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g >= whiteThreshold &&
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b >= whiteThreshold
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) {
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if (channels === 4) data[i + 3] = 0;
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else {
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// expand to RGBA if input lacked alpha
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// create a new buffer would be required; throw for simplicity
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throw new Error(
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"Input image missing alpha channel; ensure ensureAlpha() was applied.",
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);
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}
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}
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}
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// Recreate and save PNG
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await sharp(data, { raw: { width: w, height: h, channels } })
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.png({ compressionLevel: 9 })
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.toFile(outputPath);
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}
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const [, , input] = process.argv;
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if (!input) {
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throw new Error(`Input is required: input=${input}`);
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}
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// Example usage
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resizeAndMakeWhiteTransparent(input, "app-icon.png")
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.then(() => spawnSync("pnpm tauri icon", { shell: true, stdio: "inherit" }))
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.catch((err) => console.error(err));
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