Image To Papa Converter

function processImage(originalImg, fontSize = 8, backgroundColor = '#000000', word = 'ПАПА') {
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    
    // Validate font size
    let fs = parseInt(fontSize, 10);
    if (isNaN(fs) || fs < 2) fs = 8;
    
    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, width, height);
    
    let imgData;
    try {
        imgData = ctx.getImageData(0, 0, width, height);
    } catch (e) {
        console.error("CORS error: Could not read image data", e);
        // Return blank canvas if cross-origin rules prevent reading pixels
        return canvas; 
    }
    
    const data = imgData.data;
    
    // Fill the canvas with the background color
    ctx.fillStyle = backgroundColor;
    ctx.fillRect(0, 0, width, height);
    
    // Set up typography for the text mosaic
    ctx.font = `bold ${fs}px sans-serif`;
    ctx.textAlign = 'center';
    ctx.textBaseline = 'middle';
    
    const textToUse = word.length > 0 ? word : 'ПАПА';
    let charIndex = 0;
    
    // Recreate the image using the characters from the word parameter
    for (let y = fs / 2; y < height; y += fs) {
        for (let x = fs / 2; x < width; x += fs) {
            const pxX = Math.floor(x);
            const pxY = Math.floor(y);
            const pixelIndex = (pxY * width + pxX) * 4;
            
            const r = data[pixelIndex];
            const g = data[pixelIndex + 1];
            const b = data[pixelIndex + 2];
            const a = data[pixelIndex + 3];
            
            // Only draw text if the pixel is not completely transparent
            if (a > 10) {
                ctx.fillStyle = `rgba(${r}, ${g}, ${b}, ${a / 255})`;
                ctx.fillText(textToUse[charIndex], x, y);
                
                // Move to the next character in the word
                charIndex = (charIndex + 1) % textToUse.length;
            }
        }
    }
    
    return canvas;
}