G-Major By Ltv Mca Image Effect Generator

function processImage(originalImg, intensity = "1.0", rgbShift = "3") {
    // Parse parameters
    const intensityVal = parseFloat(intensity) || 1.0;
    const shiftVal = parseInt(rgbShift, 10) || 3;

    // Create and set up the canvas
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    const width = originalImg.width;
    const height = originalImg.height;
    
    canvas.width = width;
    canvas.height = height;

    // Draw original image to extract pixel data
    ctx.drawImage(originalImg, 0, 0);
    const imageData = ctx.getImageData(0, 0, width, height);
    const data = imageData.data;
    const outData = new Uint8ClampedArray(data.length);

    // G-Major by Ltv Mca effect typically involves:
    // 1. Color inversion
    // 2. High contrast
    // 3. Strong red/warm bias
    // 4. Slight chromatic aberration (RGB channel shift)

    for (let y = 0; y < height; y++) {
        for (let x = 0; x < width; x++) {
            const i = (y * width + x) * 4;
            
            // Calculate shifted X positions for Chromatic Aberration
            const xShiftedRed = Math.max(0, x - shiftVal);
            const xShiftedBlue = Math.min(width - 1, x + shiftVal);
            
            const iRed = (y * width + xShiftedRed) * 4;
            const iBlue = (y * width + xShiftedBlue) * 4;

            // Fetch inverted shifted colors
            let r = 255 - data[iRed];       // Red channel (shifted left, inverted)
            let g = 255 - data[i + 1];      // Green channel (center, inverted)
            let b = 255 - data[iBlue + 2];  // Blue channel (shifted right, inverted)
            const a = data[i + 3];

            // Apply high contrast
            r = ((r / 255 - 0.5) * 1.6 * intensityVal + 0.5) * 255;
            g = ((g / 255 - 0.5) * 1.3 * intensityVal + 0.5) * 255;
            b = ((b / 255 - 0.5) * 1.1 * intensityVal + 0.5) * 255;

            // Apply the characteristic G-Major red/orange hue tint
            r += 70 * intensityVal;   // Boost Red
            g += 15 * intensityVal;   // Slightly boost Green to push towards orange/yellow
            b -= 30 * intensityVal;   // Reduce Blue to make it warmer/creepier

            // Clamp and assign back
            outData[i] = Math.max(0, Math.min(255, r));
            outData[i + 1] = Math.max(0, Math.min(255, g));
            outData[i + 2] = Math.max(0, Math.min(255, b));
            outData[i + 3] = a; // Keep original alpha
        }
    }

    // Put modified image data back onto the canvas
    const modifiedImageData = new ImageData(outData, width, height);
    ctx.putImageData(modifiedImageData, 0, 0);

    return canvas;
}