Image To Realistic IPhone Style JPEG Converter With Custom Metadata

async function processImage(
    originalImg,
    make = "Apple",
    model = "iPhone 17",
    dateTime = "2026:07:07 21:15:00",
    latitude = -43.5320,
    longitude = 172.6362,
    quality = 0.92
) {
    // 1. Dynamically load piexifjs for Exif metadata injection
    await new Promise((resolve, reject) => {
        if (window.piexif) {
            resolve();
            return;
        }
        const script = document.createElement('script');
        script.src = 'https://cdnjs.cloudflare.com/ajax/libs/piexifjs/1.0.6/piexif.js';
        script.onload = resolve;
        script.onerror = () => reject(new Error('Failed to load piexifjs'));
        document.head.appendChild(script);
    });

    // 2. Create canvas and draw the image with an "iPhone Style" filter
    const canvas = document.createElement('canvas');
    canvas.width = originalImg.width;
    canvas.height = originalImg.height;
    const ctx = canvas.getContext('2d');

    // Mimic the modern iPhone processing (Smart HDR look): slight contrast, saturation boost, and very slight warmth
    ctx.filter = "contrast(1.08) saturate(1.15) brightness(1.02) sepia(0.04)";
    ctx.drawImage(originalImg, 0, 0);
    ctx.filter = "none";

    // 3. Convert to JPEG base64
    const jpegDataUrl = canvas.toDataURL('image/jpeg', Number(quality));

    // 4. Construct EXIF Metadata
    // Helper function to convert decimal degrees to GPS rational format Arrays expected by Exif
    function getDmsRational(deg) {
        const absolute = Math.abs(deg);
        const degrees = Math.floor(absolute);
        const minutesNotTruncated = (absolute - degrees) * 60;
        const minutes = Math.floor(minutesNotTruncated);
        const seconds = Math.round((minutesNotTruncated - minutes) * 60 * 100);
        return [[degrees, 1], [minutes, 1], [seconds, 100]];
    }

    const lat = Number(latitude);
    const lng = Number(longitude);
    const latRef = lat < 0 ? "S" : "N";
    const lngRef = lng < 0 ? "W" : "E";

    // Build Exif standard structure
    const exifObj = {
        "0th": {
            [piexif.ImageIFD.Make]: make,
            [piexif.ImageIFD.Model]: model,
            [piexif.ImageIFD.Software]: "iOS 19.4.1", // Future iOS version guess for 2026
            [piexif.ImageIFD.DateTime]: dateTime
        },
        "Exif": {
            [piexif.ExifIFD.DateTimeOriginal]: dateTime,
            [piexif.ExifIFD.DateTimeDigitized]: dateTime,
            [piexif.ExifIFD.ColorSpace]: 1, // sRGB
            [piexif.ExifIFD.PixelXDimension]: canvas.width,
            [piexif.ExifIFD.PixelYDimension]: canvas.height,
            [piexif.ExifIFD.LensMake]: make,
            [piexif.ExifIFD.LensModel]: `${model} back main camera 24mm f/1.78`
        },
        "GPS": {
            [piexif.GPSIFD.GPSLatitudeRef]: latRef,
            [piexif.GPSIFD.GPSLatitude]: getDmsRational(lat),
            [piexif.GPSIFD.GPSLongitudeRef]: lngRef,
            [piexif.GPSIFD.GPSLongitude]: getDmsRational(lng)
        }
    };

    // 5. Inject EXIF into the JPEG Data URL
    const exifBytes = piexif.dump(exifObj);
    const finalJpegDataUrl = piexif.insert(exifBytes, jpegDataUrl);

    // 6. Return as a new Image element for display or download
    return new Promise((resolve) => {
        const finalImg = new Image();
        finalImg.onload = () => resolve(finalImg);
        finalImg.src = finalJpegDataUrl;
    });
}