memowake-front/lib/image-process/imageCompress.ts

import * as ImageManipulator from 'expo-image-manipulator';
import { Image } from 'react-native';

// 压缩图片，自动等比缩放，最大边不超过 800
export const compressImage = async (uri: string, maxSize = 800): Promise<{ uri: string; file: File }> => {
    // 获取原图尺寸
    const getImageSize = (uri: string): Promise<{ width: number; height: number }> =>
        new Promise((resolve, reject) => {
            Image.getSize(
                uri,
                (width, height) => resolve({ width, height }),
                reject
            );
        });

    try {
        const { width, height } = await getImageSize(uri);
        let targetWidth = width;
        let targetHeight = height;
        if (width > maxSize || height > maxSize) {
            if (width > height) {
                targetWidth = maxSize;
                targetHeight = Math.round((height / width) * maxSize);
            } else {
                targetHeight = maxSize;
                targetWidth = Math.round((width / height) * maxSize);
            }
        }

        const manipResult = await ImageManipulator.manipulateAsync(
            uri,
            [
                {
                    resize: {
                        width: targetWidth,
                        height: targetHeight,
                    },
                },
            ],
            {
                compress: 0.7,
                format: ImageManipulator.SaveFormat.WEBP,
                base64: false,
            }
        );

        const response = await fetch(manipResult.uri);
        const blob = await response.blob();
        const filename = uri.split('/').pop() || `image_${Date.now()}.webp`;
        const file = new File([blob], filename, { type: 'image/webp' });

        return { uri: manipResult.uri, file };
    } catch (error) {
        throw error;
    }
};