TVRip Quality Image Downloader

function processImage(originalImg, noiseLevel = 25, colorBleed = 3, scanlineIntensity = 0.2, interlacingAmount = 1.5) {
    // Ensure parameters are parsed as numbers
    noiseLevel = Number(noiseLevel);
    colorBleed = Number(colorBleed);
    scanlineIntensity = Number(scanlineIntensity);
    interlacingAmount = Number(interlacingAmount);

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

    // Apply basic soft/washed-out filter characteristic of TVRips or old VHS captures
    ctx.filter = 'contrast(0.85) saturate(0.8) blur(0.8px)';
    ctx.drawImage(originalImg, 0, 0);
    ctx.filter = 'none';

    // Pixel manipulation for Color Bleed (Chromatic Aberration), Interlacing, and Noise
    let imageData;
    try {
        imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
    } catch (e) {
        // Fallback if cross-origin image taints the canvas
        return canvas; 
    }
    
    const data = imageData.data;
    const copyData = new Uint8ClampedArray(data);

    for (let y = 0; y < canvas.height; y++) {
        // Simulate interlacing comb artifacts by shifting alternate lines in opposite directions
        const interlaceShift = (y % 2 === 0) ? Math.floor(interlacingAmount) : -Math.floor(interlacingAmount);

        for (let x = 0; x < canvas.width; x++) {
            const i = (y * canvas.width + x) * 4;

            // Combine color bleed (RGB separation) and interlacing shifts
            const redX = Math.min(canvas.width - 1, Math.max(0, x - colorBleed + interlaceShift));
            const redI = (y * canvas.width + redX) * 4;

            const greenX = Math.min(canvas.width - 1, Math.max(0, x + interlaceShift));
            const greenI = (y * canvas.width + greenX) * 4;

            const blueX = Math.min(canvas.width - 1, Math.max(0, x + colorBleed + interlaceShift));
            const blueI = (y * canvas.width + blueX) * 4;

            data[i] = copyData[redI];         // Red channel
            data[i + 1] = copyData[greenI + 1]; // Green channel
            data[i + 2] = copyData[blueI + 2];  // Blue channel

            // Add TV static noise (Luma overlay)
            const noise = (Math.random() - 0.5) * noiseLevel;
            data[i] = Math.min(255, Math.max(0, data[i] + noise));
            data[i + 1] = Math.min(255, Math.max(0, data[i + 1] + noise));
            data[i + 2] = Math.min(255, Math.max(0, data[i + 2] + noise));
        }
    }
    
    ctx.putImageData(imageData, 0, 0);

    // Apply Horizontal Scanlines (CRT Effect)
    ctx.fillStyle = `rgba(0, 0, 0, ${scanlineIntensity})`;
    for (let y = 0; y < canvas.height; y += 2) {
        ctx.fillRect(0, y, canvas.width, 1);
    }

    // Apply subtle Vertical RGB Shadow Mask (CRT phosphor effect)
    ctx.fillStyle = `rgba(255, 0, 0, ${scanlineIntensity * 0.15})`;
    for (let x = 0; x < canvas.width; x += 3) {
        ctx.fillRect(x, 0, 1, canvas.height);
    }
    ctx.fillStyle = `rgba(0, 255, 0, ${scanlineIntensity * 0.15})`;
    for (let x = 1; x < canvas.width; x += 3) {
        ctx.fillRect(x, 0, 1, canvas.height);
    }
    ctx.fillStyle = `rgba(0, 0, 255, ${scanlineIntensity * 0.15})`;
    for (let x = 2; x < canvas.width; x += 3) {
        ctx.fillRect(x, 0, 1, canvas.height);
    }

    // Apply Tube TV Vignette (Darkening corners on the screen)
    const gradient = ctx.createRadialGradient(
        canvas.width / 2, canvas.height / 2, canvas.height * 0.3,
        canvas.width / 2, canvas.height / 2, Math.max(canvas.width, canvas.height) * 0.6
    );
    gradient.addColorStop(0, 'rgba(0, 0, 0, 0)');
    gradient.addColorStop(1, 'rgba(0, 0, 0, 0.7)');
    
    ctx.fillStyle = gradient;
    ctx.fillRect(0, 0, canvas.width, canvas.height);

    return canvas;
}