HarmonyOS 图片压缩示例？

import image from '@ohos.multimedia.image';
import fileio from '@ohos.fileio';
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function readImageFile(filePath: string): ArrayBuffer {
    const file = fileio.openSync(filePath, fileio.OpenMode.READ_ONLY);
    const stat = fileio.statSync(filePath);
    const buffer = new ArrayBuffer(stat.size);
    fileio.readSync(file.fd, buffer);
    fileio.closeSync(file);
    return buffer;
}
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async function compressImage(inputPath: string, outputPath: string, targetSizeKB: number) {
    const imagePacker = image.createImagePacker();

    // 读取原始图片数据
    const imageData = readImageFile(inputPath);

    // 配置压缩参数
    const packingOptions = {
        format: 'image/jpeg', // 支持 jpeg、webp、png 
        quality: 85,         // 初始质量（0-100）
    };

    // 使用二分法查找最接近目标大小的质量值
    let lowQuality = 0;
    let highQuality = 100;
    let bestQuality = 85;

    while (lowQuality <= highQuality) {
        const midQuality = Math.floor((lowQuality + highQuality) / 2);
        packingOptions.quality = midQuality;

        // 压缩图片并保存到临时文件
        await imagePacker.packing(imageData, packingOptions).then((compressedData) => {
            const compressedSizeKB = compressedData.byteLength / 1024;

            if (compressedSizeKB <= targetSizeKB) {
                bestQuality = midQuality; // 记录最佳质量
                lowQuality = midQuality + 1; // 尝试更高的质量
            } else {
                highQuality = midQuality - 1; // 尝试更低的质量
            }
        });
    }

    // 使用最佳质量重新压缩图片
    packingOptions.quality = bestQuality;
    const finalCompressedData = await imagePacker.packing(imageData, packingOptions);

    // 将压缩后的图片写入目标文件
    const outputFile = fileio.openSync(outputPath, fileio.OpenMode.CREATE | fileio.OpenMode.WRITE_ONLY);
    fileio.writeSync(outputFile.fd, finalCompressedData);
    fileio.closeSync(outputFile);

    console.log(`Image compressed successfully. Final size: ${finalCompressedData.byteLength / 1024} KB`);
}
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compressImage('/path/to/input.jpg', '/path/to/output.jpg', 200)
    .then(() => {
        console.log('Compression completed.');
    })
    .catch((err) => {
        console.error('Compression failed:', err);
    });
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"requestPermissions": [
    "ohos.permission.READ_USER_STORAGE",
    "ohos.permission.WRITE_USER_STORAGE"
]
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