You can edit the below JavaScript code to customize the image tool.
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function processImage(originalImg, outlineColor = '#FF0000', highlightColor = '#00FF00') {
const width = 1280;
const height = 720; // Standard YouTube thumbnail resolution
const canvas = document.createElement('canvas');
canvas.width = width;
canvas.height = height;
const ctx = canvas.getContext('2d');
// 1. Draw and scale original image to proportionally cover the 1280x720 canvas
const imgRatio = originalImg.width / originalImg.height;
const canvasRatio = width / height;
let drawWidth, drawHeight, offsetX, offsetY;
if (imgRatio > canvasRatio) {
drawHeight = height;
drawWidth = originalImg.width * (height / originalImg.height);
offsetX = (width - drawWidth) / 2;
offsetY = 0;
} else {
drawWidth = width;
drawHeight = originalImg.height * (width / originalImg.width);
offsetX = 0;
offsetY = (height - drawHeight) / 2;
}
// High quality scaling
ctx.imageSmoothingEnabled = true;
ctx.imageSmoothingQuality = 'high';
ctx.drawImage(originalImg, offsetX, offsetY, drawWidth, drawHeight);
// 2. Perform Image Analysis (Brightness, Contrast, etc. for "Identifier" logic)
const imgData = ctx.getImageData(0, 0, width, height);
const data = imgData.data;
let totalBrightness = 0;
// Quick estimation for performance (sampling every 16th pixel)
let sampleCount = 0;
for (let i = 0; i < data.length; i += 4 * 4) {
const r = data[i];
const g = data[i + 1];
const b = data[i + 2];
const lum = 0.299 * r + 0.587 * g + 0.114 * b;
totalBrightness += lum;
sampleCount++;
}
const avgBrightness = totalBrightness / sampleCount;
// Calculate contrast (standard deviation of luminance)
let varianceSum = 0;
for (let i = 0; i < data.length; i += 4 * 4) {
const r = data[i];
const g = data[i + 1];
const b = data[i + 2];
const lum = 0.299 * r + 0.587 * g + 0.114 * b;
varianceSum += Math.pow(lum - avgBrightness, 2);
}
const contrast = Math.sqrt(varianceSum / sampleCount);
// Simulate an engagement probability score based on thumbnail brightness and contrast
const score = Math.min(99, Math.floor(((contrast / 80) * 60) + ((avgBrightness / 255) * 40)));
// 3. Draw Scan Overlay (Vignette for focus)
const gradient = ctx.createRadialGradient(width / 2, height / 2, height / 3, width / 2, height / 2, height);
gradient.addColorStop(0, 'rgba(0,0,0,0)');
gradient.addColorStop(1, 'rgba(0,0,0,0.6)');
ctx.fillStyle = gradient;
ctx.fillRect(0, 0, width, height);
// 4. Rule of Thirds Grid (Standard composition tool)
ctx.strokeStyle = 'rgba(255, 255, 255, 0.25)';
ctx.lineWidth = 1;
ctx.setLineDash([10, 10]);
ctx.beginPath();
for (let i = 1; i < 3; i++) {
// Vertical lines
ctx.moveTo(width * i / 3, 0);
ctx.lineTo(width * i / 3, height);
// Horizontal lines
ctx.moveTo(0, height * i / 3);
ctx.lineTo(width, height * i / 3);
}
ctx.stroke();
ctx.setLineDash([]); // Reset line dash
// 5. HUD Corner Brackets
const bracketSize = 80;
const padding = 40;
ctx.strokeStyle = outlineColor;
ctx.lineWidth = 4;
ctx.beginPath();
// Top Left
ctx.moveTo(padding + bracketSize, padding);
ctx.lineTo(padding, padding);
ctx.lineTo(padding, padding + bracketSize);
// Top Right
ctx.moveTo(width - padding - bracketSize, padding);
ctx.lineTo(width - padding, padding);
ctx.lineTo(width - padding, padding + bracketSize);
// Bottom Left
ctx.moveTo(padding + bracketSize, height - padding);
ctx.lineTo(padding, height - padding);
ctx.lineTo(padding, height - padding - bracketSize);
// Bottom Right
ctx.moveTo(width - padding - bracketSize, height - padding);
ctx.lineTo(width - padding, height - padding);
ctx.lineTo(width - padding, height - padding - bracketSize);
ctx.stroke();
// 6. Center Crosshairs
ctx.strokeStyle = 'rgba(255, 255, 255, 0.6)';
ctx.lineWidth = 2;
ctx.beginPath();
ctx.moveTo(width / 2 - 30, height / 2);
ctx.lineTo(width / 2 + 30, height / 2);
ctx.moveTo(width / 2, height / 2 - 30);
ctx.lineTo(width / 2, height / 2 + 30);
ctx.stroke();
ctx.beginPath();
ctx.arc(width / 2, height / 2, 15, 0, 2 * Math.PI);
ctx.stroke();
// 7. Data Analytics Panel (Bottom Left)
const panelWidth = 400;
const panelHeight = 200;
const panelX = padding;
const panelY = height - padding - panelHeight;
ctx.fillStyle = 'rgba(10, 10, 10, 0.8)';
ctx.fillRect(panelX, panelY, panelWidth, panelHeight);
ctx.strokeStyle = outlineColor;
ctx.lineWidth = 2;
ctx.strokeRect(panelX, panelY, panelWidth, panelHeight);
// Text formatting setup
ctx.font = 'bold 16px "Courier New", Courier, monospace';
ctx.textBaseline = 'top';
const textPadX = panelX + 20;
let curY = panelY + 20;
// Output HUD Text
ctx.fillStyle = outlineColor;
ctx.fillText('► YOUTUBE THUMBNAIL SCANNER', textPadX, curY);
curY += 30;
ctx.fillStyle = '#FFFFFF';
ctx.fillText(`ORIGINAL DIM.: ${originalImg.width}x${originalImg.height}px`, textPadX, curY);
curY += 25;
const isOptRatio = Math.abs(imgRatio - (16 / 9)) < 0.05;
ctx.fillStyle = isOptRatio ? highlightColor : '#FFCC00';
ctx.fillText(`ASPECT RATIO : ${imgRatio.toFixed(2)} ` + (isOptRatio ? '[OPTIMAL 16:9]' : '[WARNING]'), textPadX, curY);
curY += 25;
ctx.fillStyle = '#FFFFFF';
ctx.fillText(`LUMINANCE LVL: ${Math.round(avgBrightness)}/255`, textPadX, curY);
curY += 25;
const contrastStatus = contrast > 50 ? 'HIGH [IDEAL]' : (contrast > 25 ? 'MODERATE' : 'LOW [FIX REQ]');
ctx.fillStyle = contrast > 50 ? highlightColor : (contrast > 25 ? '#FFCC00' : '#FF0000');
ctx.fillText(`CONTRAST CLS : ${contrastStatus}`, textPadX, curY);
curY += 25;
ctx.fillStyle = score >= 60 ? highlightColor : '#FFCC00';
ctx.fillText(`EST. CTR POT.: ${score}%`, textPadX, curY);
// 8. Visual Focus Box (Simulating Subject Detection)
const focusBoxW = width * 0.35;
const focusBoxH = height * 0.6;
const focusBoxX = (width / 2) + Math.cos(score) * 100 - (focusBoxW / 2); // Slightly offset based on score randomness
const focusBoxY = (height / 2) - (focusBoxH / 2);
ctx.strokeStyle = highlightColor;
ctx.lineWidth = 2;
ctx.strokeRect(focusBoxX, focusBoxY, focusBoxW, focusBoxH);
// Inner focal point marker
ctx.fillStyle = highlightColor;
ctx.fillRect(focusBoxX - 5, focusBoxY - 5, 10, 10);
ctx.fillRect(focusBoxX + focusBoxW - 5, focusBoxY - 5, 10, 10);
ctx.fillRect(focusBoxX - 5, focusBoxY + focusBoxH - 5, 10, 10);
ctx.fillRect(focusBoxX + focusBoxW - 5, focusBoxY + focusBoxH - 5, 10, 10);
ctx.font = '14px "Courier New", Courier, monospace';
ctx.fillText('SUBJECT_SYS_LOC', focusBoxX + 10, focusBoxY + 10);
// 9. Mock "Scanning" line overlay
ctx.beginPath();
ctx.moveTo(padding, height * 0.45);
ctx.lineTo(width - padding, height * 0.45);
ctx.strokeStyle = 'rgba(255, 0, 0, 0.4)';
ctx.lineWidth = 3;
ctx.stroke();
// 10. Simulated Barcode / Tech Identifier (Top Right)
ctx.fillStyle = 'rgba(255, 255, 255, 0.8)';
let bcX = width - padding - 220;
const bcY = padding;
for(let i = 0; i < 35; i++) {
let barW = Math.random() * 4 + 1;
ctx.fillRect(bcX, bcY, barW, 40);
bcX += barW + Math.random() * 4 + 1;
if (bcX > width - padding - 10) break;
}
ctx.font = '12px "Courier New", Courier, monospace';
ctx.fillText('SCAN_ID: YT-' + Math.floor(Math.random()*90000 + 10000), width - padding - 220, bcY + 50);
// 11. Mock YouTube Overlay Player button (Bottom Right)
const drawRoundedRect = (ctx, x, y, w, h, r) => {
ctx.beginPath();
ctx.moveTo(x + r, y);
ctx.lineTo(x + w - r, y);
ctx.arcTo(x + w, y, x + w, y + h, r);
ctx.lineTo(x + w, y + h - r);
ctx.arcTo(x + w, y + h, x + w - r, y + h, r);
ctx.lineTo(x + r, y + h);
ctx.arcTo(x, y + h, x, y + h - r, r);
ctx.lineTo(x, y + r);
ctx.arcTo(x, y, x + r, y, r);
ctx.closePath();
};
ctx.fillStyle = 'rgba(0, 0, 0, 0.8)';
drawRoundedRect(ctx, width - padding - 80, height - padding - 50, 80, 50, 12);
ctx.fill();
ctx.fillStyle = outlineColor;
drawRoundedRect(ctx, width - padding - 80, height - padding - 50, 80, 50, 12);
ctx.fill();
ctx.fillStyle = '#FFFFFF';
ctx.beginPath();
ctx.moveTo(width - padding - 50, height - padding - 35);
ctx.lineTo(width - padding - 50, height - padding - 15);
ctx.lineTo(width - padding - 30, height - padding - 25);
ctx.closePath();
ctx.fill();
return canvas;
}Apply Changes
