cs249r_book/tinytorch/site/extra/community/modules/utils.js

// Helper to resize images
export function resizeImage(file, maxWidth, maxHeight, quality) {
    return new Promise((resolve, reject) => {
        const reader = new FileReader();
        reader.onload = (event) => {
            const img = new Image();
            img.onload = () => {
                let width = img.width;
                let height = img.height;

                if (width > height) {
                    if (width > maxWidth) {
                        height = Math.round((height * maxWidth) / width);
                        width = maxWidth;
                    }
                } else {
                    if (height > maxHeight) {
                        width = Math.round((width * maxHeight) / height);
                        height = maxHeight;
                    }
                }

                const canvas = document.createElement('canvas');
                canvas.width = width;
                canvas.height = height;
                const ctx = canvas.getContext('2d');
                ctx.drawImage(img, 0, 0, width, height);

                resolve(canvas.toDataURL('image/jpeg', quality));
            };
            img.onerror = (err) => reject(err);
            img.src = event.target.result;
        };
        reader.onerror = (err) => reject(err);
        reader.readAsDataURL(file);
    });
}