Nikita8500HD Major Image Effect Generator

function processImage(originalImg, invertPercent = 100, hueRotateDeg = 0, saturationPercent = 250, contrastPercent = 150, rgbSplitDistance = 3, mirrorMode = 'none') {
    // Parse and sanitize parameters
    invertPercent = Number(invertPercent);
    hueRotateDeg = Number(hueRotateDeg);
    saturationPercent = Number(saturationPercent);
    contrastPercent = Number(contrastPercent);
    rgbSplitDistance = Math.floor(Number(rgbSplitDistance));
    
    // Normalize mirrorMode parameter
    mirrorMode = String(mirrorMode).trim().toLowerCase();

    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    
    const width = originalImg.width;
    const height = originalImg.height;
    canvas.width = width;
    canvas.height = height;

    // Apply primary effect via Canvas filter.
    // The "Major" effect typically relies tightly on intense color inversion, boosted contrast, and adjusted saturation levels.
    ctx.filter = `invert(${invertPercent}%) hue-rotate(${hueRotateDeg}deg) saturate(${saturationPercent}%) contrast(${contrastPercent}%)`;
    ctx.drawImage(originalImg, 0, 0);
    
    // Reset filter for subsequent operations
    ctx.filter = 'none';

    // Apply Chromatic Aberration / RGB Split, which is highly common in "HD" YTPMV/Meme visual effects
    if (rgbSplitDistance > 0) {
        const imageData = ctx.getImageData(0, 0, width, height);
        const data = imageData.data;
        const outData = new Uint8ClampedArray(data);

        for (let y = 0; y < height; y++) {
            for (let x = 0; x < width; x++) {
                const i = (y * width + x) * 4;
                
                // Shift Red Channel Left
                const shiftRedX = Math.min(width - 1, Math.max(0, x - rgbSplitDistance));
                const idxRed = (y * width + shiftRedX) * 4;

                // Shift Blue Channel Right
                const shiftBlueX = Math.min(width - 1, Math.max(0, x + rgbSplitDistance));
                const idxBlue = (y * width + shiftBlueX) * 4;

                outData[i] = data[idxRed];           // Red channel shifted
                outData[i + 1] = data[i + 1];        // Green channel neutral (untouched)
                outData[i + 2] = data[idxBlue + 2];  // Blue channel shifted
                outData[i + 3] = data[i + 3];        // Alpha neutral
            }
        }
        imageData.data.set(outData);
        ctx.putImageData(imageData, 0, 0);
    }

    // Apply Mirroring Effects (Also prominent in similar generators)
    if (mirrorMode === 'left-to-right' || mirrorMode === 'right-to-left' || mirrorMode === 'top-to-bottom' || mirrorMode === 'bottom-to-top') {
        const tempCanvas = document.createElement('canvas');
        tempCanvas.width = width;
        tempCanvas.height = height;
        const tCtx = tempCanvas.getContext('2d');

        if (mirrorMode === 'left-to-right' || mirrorMode === 'right-to-left') {
            tCtx.translate(width, 0);
            tCtx.scale(-1, 1);
            tCtx.drawImage(canvas, 0, 0);
            
            if (mirrorMode === 'left-to-right') {
                // Takes the mirrored left side onto the right side
                ctx.drawImage(tempCanvas, width / 2, 0, width / 2, height, width / 2, 0, Math.ceil(width / 2), height);
            } else if (mirrorMode === 'right-to-left') {
                // Takes the mirrored right side onto the left side
                ctx.drawImage(tempCanvas, 0, 0, Math.ceil(width / 2), height, 0, 0, Math.ceil(width / 2), height);
            }
        } else if (mirrorMode === 'top-to-bottom' || mirrorMode === 'bottom-to-top') {
            tCtx.translate(0, height);
            tCtx.scale(1, -1);
            tCtx.drawImage(canvas, 0, 0);
            
            if (mirrorMode === 'top-to-bottom') {
                ctx.drawImage(tempCanvas, 0, height / 2, width, height / 2, 0, height / 2, width, Math.ceil(height / 2));
            } else if (mirrorMode === 'bottom-to-top') {
                ctx.drawImage(tempCanvas, 0, 0, width, height / 2, 0, 0, width, Math.ceil(height / 2));
            }
        }
    }

    return canvas;
}