Red Head Sound Major Image Effect Generator

function processImage(originalImg, effectIntensity = "100", applyInversion = "true", redBoostMultiplier = "2.5", addWatermark = "true") {
    // Create canvas matching original image dimensions
    const canvas = document.createElement('canvas');
    const width = originalImg.width;
    const height = originalImg.height;
    canvas.width = width;
    canvas.height = height;

    const ctx = canvas.getContext('2d');
    
    // Draw original image on the canvas
    ctx.drawImage(originalImg, 0, 0, width, height);

    // Extract image data for pixel manipulation
    const imgData = ctx.getImageData(0, 0, width, height);
    const data = imgData.data;

    // Parse parameters
    const intensity = Math.max(0, Math.min(100, parseFloat(effectIntensity))) / 100;
    const invert = String(applyInversion).toLowerCase() === "true";
    const rMult = parseFloat(redBoostMultiplier) || 2.5;

    // Apply the "Major" visual effect
    // G-Major and similar effects typically invert colors and heavily tint red
    for (let i = 0; i < data.length; i += 4) {
        const origR = data[i];
        const origG = data[i + 1];
        const origB = data[i + 2];
        
        let r, g, b;

        if (invert) {
            r = 255 - origR;
            g = 255 - origG;
            b = 255 - origB;
        } else {
            r = origR;
            g = origG;
            b = origB;
        }

        // Apply red bias and color distortion
        r = Math.min(255, r * rMult);
        g = Math.min(255, g * 0.6); // Suppress green
        b = Math.min(255, b * 0.4); // Suppress blue heavily

        // Blend with the original image based on intensity value
        data[i] = origR + (r - origR) * intensity;
        data[i + 1] = origG + (g - origG) * intensity;
        data[i + 2] = origB + (b - origB) * intensity;
        
        // Alpha channel (data[i + 3]) is left untouched
    }

    // Put modified data back onto the canvas
    ctx.putImageData(imgData, 0, 0);

    // Add optional "Red Head Sound" loud text watermark (classic meme/YTP style)
    if (String(addWatermark).toLowerCase() === "true") {
        const fontSize = Math.max(25, width / 18);
        ctx.font = `900 ${fontSize}px "Impact", "Arial Black", sans-serif`;
        ctx.textAlign = "center";
        ctx.textBaseline = "bottom";

        const text = "RED HEAD SOUND";
        const x = width / 2;
        const y = height - (height * 0.05);

        // Text stroke (outline)
        ctx.lineWidth = Math.max(3, fontSize / 10);
        ctx.strokeStyle = "#000000";
        ctx.strokeText(text, x, y);

        // Text fill
        ctx.fillStyle = "#FF0000";
        ctx.fillText(text, x, y);
    }

    return canvas;
}