ARTICLE AD BOX
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>TrueTone | Industrial Calibration</title>
<style>
/* CSS RESET & VARIABLES */
:root {
--bg-color: #0f0f0f; --text-main: #e0e0e0; --text-muted: #9e9e9e;
--accent: #ffffff; --border: #333333; --success: #4CAF50;
--fail: #F44336; --cyan: #00bcd4; --magenta: #e91e63; --yellow: #FFC107;
--grid-color: #2a2a2c;
--font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
--font-mono: "Courier New", Courier, monospace;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { background-color: var(--bg-color); color: var(--text-main); font-family: var(--font-main); line-height: 1.6; padding-bottom: 5rem; overflow-x: hidden; }
h2 { text-transform: uppercase; letter-spacing: 2px; margin-bottom: 1.5rem; font-weight: 900; }
.container { max-width: 1050px; margin: 0 auto; padding: 0 2rem; position: relative; }
header { padding: 2rem 0; display: flex; justify-content: space-between; align-items: center; border-bottom: 2px solid var(--border); margin-bottom: 3rem;}
.logo { font-family: var(--font-main); font-size: 1.8rem; font-weight: 900; letter-spacing: 4px; color: var(--accent); border: 3px solid var(--accent); padding: 8px 16px; border-radius: 4px; text-transform: uppercase;}
.user-badge { display: flex; align-items: center; gap: 15px; flex-wrap: wrap;}
.vdi-display { font-family: var(--font-mono); font-weight: bold; color: var(--cyan); border: 1px solid var(--cyan); padding: 4px 10px; border-radius: 2px; letter-spacing: 1px; transition: color 0.2s, border-color 0.2s; cursor: pointer; user-select: none;}
.vdi-display:hover { background: rgba(0, 188, 212, 0.1); box-shadow: 0 0 10px rgba(0, 188, 212, 0.2); }
.vdi-updating { color: var(--accent) !important; border-color: var(--accent) !important; }
.modal-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0, 0, 0, 0.85); backdrop-filter: blur(5px); display: flex; justify-content: center; align-items: center; z-index: 1000; }
.auth-box { background-color: #111; border: 4px solid #444; padding: 3rem; width: 100%; max-width: 450px; box-shadow: 0 20px 50px rgba(0,0,0,1); position: relative; }
.auth-header { font-family: var(--font-mono); font-size: 1.2rem; text-transform: uppercase; letter-spacing: 2px; color: #888; margin-bottom: 2rem; border-bottom: 2px dashed #444; padding-bottom: 1rem; }
.input-group { margin-bottom: 1.5rem; }
.input-group label { display: block; font-family: var(--font-mono); font-size: 0.8rem; text-transform: uppercase; color: #888; margin-bottom: 0.5rem; }
.industrial-input { width: 100%; background: #0a0a0a; border: 2px solid #333; color: var(--accent); padding: 12px; font-family: var(--font-mono); font-size: 1rem; outline: none; transition: border-color 0.2s; }
.industrial-input:focus { border-color: var(--cyan); }
.close-modal { position: absolute; top: 15px; right: 20px; color: #888; font-size: 1.5rem; cursor: pointer; font-family: var(--font-mono); }
.close-modal:hover { color: var(--accent); }
.stats-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-bottom: 1.5rem; }
.stat-card { background: #1a1a1c; border: 1px solid #333; padding: 1.5rem 1rem; text-align: center; border-radius: 4px; }
.stat-label { font-size: 0.65rem; color: #888; text-transform: uppercase; letter-spacing: 2px; }
.stat-value { font-family: var(--font-mono); font-size: 1.8rem; color: var(--accent); font-weight: bold; margin-top: 0.5rem; }
.module-box { display: grid; grid-template-columns: 80px 1fr; background-color: #161616; border: 2px solid #444; border-radius: 4px; margin: 3rem 0; box-shadow: 0 10px 30px rgba(0,0,0,0.8); min-height: 300px; overflow: hidden; }
.module-sidebar { writing-mode: vertical-rl; transform: rotate(180deg); font-size: 0.7rem; text-transform: uppercase; letter-spacing: 4px; background: #222; border-right: 1px solid #333; color: var(--cyan); display: flex; align-items: center; justify-content: center; font-weight: bold; }
.module-content { padding: 3rem 2rem; display: flex; flex-direction: column; align-items: center; width: 100%; position: relative;}
.comparison-wrapper { width: 100%; display: flex; flex-direction: column; align-items: center; margin: 1rem auto; }
.labels { display: flex; width: 288px; justify-content: space-between; margin-bottom: 0.8rem; }
.labels span { flex: 1; text-align: center; font-size: 0.8rem; letter-spacing: 2px; text-transform: uppercase; color: #888; font-weight: bold; }
.comparison-board { display: flex; justify-content: center; border: 4px solid #222; border-radius: 4px; overflow: hidden; width: 288px; box-shadow: 0 8px 25px rgba(0,0,0,0.6); }
.swatch { width: 140px; height: 140px; }
.hidden { display: none !important; }
.controls-wrapper { display: flex; align-items: center; justify-content: center; gap: 1.5rem; margin: 1rem 0; position: relative; z-index: 100; flex-wrap: wrap;}
.slider-group { display: flex; flex-direction: column; align-items: center; width: 100%; max-width: 400px; margin-bottom: 1.5rem; }
.slider-label { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 2px; color: #888; margin-bottom: 0.8rem; font-weight: bold; width: 100%; text-align: left; }
.icon-btn { background-color: #222; color: var(--accent); border: 2px solid #555; width: 45px; height: 45px; border-radius: 4px; font-size: 1.5rem; cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all 0.2s; font-weight: bold;}
.icon-btn:hover { background-color: #444; border-color: #888; }
.icon-btn:active { transform: scale(0.95); }
input[type="range"] { width: 100%; cursor: pointer; position: relative; z-index: 101; height: 12px; background: #444; outline: none; border-radius: 4px; -webkit-appearance: none; border: 1px solid #222;}
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 24px; height: 24px; background: var(--accent); border-radius: 4px; cursor: pointer; border: 2px solid #111; box-shadow: 0 2px 5px rgba(0,0,0,0.5);}
.btn-container { display: flex; flex-wrap: wrap; justify-content: center; gap: 1rem; margin-top: 1.5rem; }
.btn { background-color: #ddd; color: #111; border: 2px solid #ddd; padding: 1rem 2rem; font-size: 0.9rem; font-weight: bold; border-radius: 4px; cursor: pointer; transition: all 0.2s; text-transform: uppercase; letter-spacing: 2px; }
.btn:hover { background-color: #fff; border-color: #fff; }
.btn-outline { background-color: transparent; color: #aaa; border: 2px solid #555; }
.btn-outline:hover { background-color: #333; color: #fff; border-color: #888;}
.btn-active { background-color: var(--cyan) !important; color: #000 !important; border-color: var(--cyan) !important; box-shadow: 0 0 15px rgba(0, 188, 212, 0.4) !important;}
.result-text { margin-top: 1.5rem; font-weight: bold; font-size: 1.3rem; min-height: 28px; text-align: center; }
@keyframes slam { 0% { transform: scale(2.5); opacity: 0; } 50% { transform: scale(0.95); opacity: 1; } 100% { transform: scale(1); } }
@keyframes mechanical-shake { 0% { transform: translate(0, 0); } 20% { transform: translate(-2px, 1px); } 40% { transform: translate(2px, -1px); } 60% { transform: translate(-1px, 2px); } 80% { transform: translate(1px, -1px); } 100% { transform: translate(0, 0); } }
@keyframes slideInUp { 0% { transform: translateY(20px); opacity: 0; } 100% { transform: translateY(0); opacity: 1; } }
.feedback-stamp-container { display: flex; justify-content: center; gap: 1rem; margin-top: 2rem; flex-wrap: wrap; }
.stamp { border: 3px solid #555; border-radius: 4px; padding: 10px 15px; font-family: var(--font-main); font-weight: 900; font-size: 1.1rem; text-transform: uppercase; letter-spacing: 1px; color: #888; display: flex; align-items: center; gap: 8px; background: #111; min-width: 120px; justify-content: center;}
.stamp.ok { border-color: var(--success); color: var(--success); }
.stamp.fail { border-color: var(--fail); color: var(--fail); }
.stamp-icon { font-size: 1.3rem; }
.stamp-animated { animation: slam 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards, mechanical-shake 0.15s 0.25s ease-in-out; }
.hint-text { text-align: left; font-family: var(--font-mono); font-size: 0.9rem; margin-top: 1.5rem; border: 1px dashed #FFEB3B; padding: 15px 20px; border-radius: 4px; background: rgba(255, 235, 59, 0.05); display: inline-block; animation: slideInUp 0.3s ease-out; width: 100%; max-width: 560px; }
.diagnostic-header { color: #888; font-weight: bold; text-transform: uppercase; margin-bottom: 10px; letter-spacing: 1px; border-bottom: 1px solid #444; padding-bottom: 5px; }
.diagnostic-list { list-style-type: square; padding-left: 20px; margin: 0; line-height: 1.8; color: #e0e0e0; }
.diagnostic-list span { color: #FFEB3B; font-weight: bold; }
.procreate-workspace { position: relative; width: 100%; max-width: 800px; aspect-ratio: 16/9; background-color: #1a1a1c; border-radius: 8px; overflow: hidden; box-shadow: 0 0 0 2px #333, 0 15px 30px rgba(0,0,0,0.8), inset 0 0 40px rgba(0,0,0,0.6); margin-top: 1rem; }
.main-canvas { width: 100%; height: 100%; cursor: crosshair; touch-action: none; display: block; }
.reference-cam-container { position: absolute; top: 20px; left: 20px; width: 25%; background: #111; border: 2px solid #555; border-radius: 6px; box-shadow: 0 10px 25px rgba(0,0,0,0.9); z-index: 10; overflow: hidden; pointer-events: none; }
.reference-cam-label { background: #222; color: var(--cyan); font-family: var(--font-mono); font-size: 0.6rem; text-transform: uppercase; letter-spacing: 2px; padding: 4px 8px; border-bottom: 1px solid #444; font-weight: bold; }
.reference-canvas { width: 100%; height: auto; display: block; background: #1a1a1c; }
.floating-toolbar { position: absolute; top: 20px; right: 20px; display: flex; flex-direction: column; gap: 12px; z-index: 10; }
.tool-btn { background: rgba(17, 17, 17, 0.85); backdrop-filter: blur(8px); border: 1px solid #555; color: #ccc; font-family: var(--font-mono); font-weight: bold; text-transform: uppercase; font-size: 0.75rem; letter-spacing: 1px; padding: 12px 15px; border-radius: 6px; cursor: pointer; transition: all 0.2s; box-shadow: 0 5px 15px rgba(0,0,0,0.5); }
.tool-btn:hover { background: #333; color: #fff; border-color: #888; }
.verify-btn { background: var(--accent); color: #000; margin-top: 10px; border-color: var(--accent); }
.verify-btn:hover { background: var(--success); border-color: var(--success); }
.floating-result { position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%); background: rgba(0,0,0,0.8); padding: 10px 20px; border-radius: 4px; border: 1px solid #444; font-family: var(--font-mono); font-size: 1rem; font-weight: bold; z-index: 10; white-space: nowrap; }
.loading-screen { position: absolute; top: 0; left: 0; width: 100%; height: 100%; background: #1a1a1c; display: flex; flex-direction: column; justify-content: center; align-items: center; z-index: 15; font-family: var(--font-mono); color: var(--cyan); text-transform: uppercase; letter-spacing: 2px; text-align: center; padding: 20px; }
.loading-sub { font-size: 0.7rem; color: #888; margin-top: 10px; }
.metadata-tag { position: absolute; bottom: 10px; left: 20px; background: rgba(0,0,0,0.7); padding: 5px 10px; border-radius: 4px; border: 1px solid #444; font-family: var(--font-mono); font-size: 0.7rem; color: #888; pointer-events: none; z-index: 10; }
.floating-reward { position: absolute; font-family: var(--font-mono); font-weight: bold; text-shadow: 0 2px 10px rgba(0,0,0,1); pointer-events: none; z-index: 2000; transition: all 1.2s cubic-bezier(0.25, 1, 0.5, 1); display: flex; flex-direction: column; align-items: center; }
.reward-credits { font-size: 1.2rem; color: var(--success); }
.reward-vdi { font-size: 0.9rem; color: var(--cyan); margin-top: -5px; }
</style>
</head>
<body>
<div id="authModal" class="modal-overlay hidden">
<div class="auth-box">
<span class="close-modal" id="closeModal">X</span>
<div class="auth-header" id="authTitle">Secure Access Port</div>
<div class="input-group"><label>Callsign / Username</label><input type="text" id="authUsername" class="industrial-input" placeholder="ENTER ID"></div>
<div class="input-group"><label>Passcode</label><input type="password" id="authPassword" class="industrial-input" placeholder="••••••••"></div>
<div id="authError" class="stamp fail hidden" style="margin-bottom: 1.5rem; font-size: 0.9rem; padding: 5px;"><span class="stamp-icon">🚫</span> AUTH FAILED</div>
<button class="btn" id="submitAuthBtn" style="width: 100%; margin: 0;">Initialize</button>
<p style="text-align: center; margin-top: 1rem; font-size: 0.8rem; font-family: var(--font-mono); cursor: pointer;" id="toggleAuthMode">New User? Register Here.</p>
</div>
</div>
<div id="statsModal" class="modal-overlay hidden">
<div class="auth-box" style="max-width: 650px;">
<span class="close-modal" id="closeStatsModal">X</span>
<div class="auth-header">Telemetric Profile Log</div>
<div class="stats-grid">
<div class="stat-card"><div class="stat-label">Value Drift</div><div class="stat-value" id="statValueVDI">--</div></div>
<div class="stat-card"><div class="stat-label">Chroma Drift</div><div class="stat-value" id="statChromaVDI">--</div></div>
<div class="stat-card"><div class="stat-label">Spatial Drift</div><div class="stat-value" id="statSpatialVDI">--</div></div>
<div class="stat-card"><div class="stat-label">Anchor Extrema</div><div class="stat-value" id="statAnchorVDI" style="color: var(--cyan);">--</div></div>
</div>
<p style="text-align: center; font-size: 0.8rem; color: #666; font-family: var(--font-mono); text-transform: uppercase;">Total Shifts Logged: <span id="statTotalRounds" style="color: var(--success); font-weight: bold;">--</span></p>
<div class="hint-text" style="width: 100%; max-width: 100%; margin-top: 1rem;">
<div class="diagnostic-header">Perception Bias Insight</div>
<div id="diagnosticInsight" style="color: #e0e0e0; line-height: 1.6;">Insufficient data. Clock in and complete more shifts.</div>
</div>
</div>
</div>
<div class="container">
<header>
<div class="logo">TRUETONE</div>
<nav id="navArea"><button class="btn btn-outline" id="loginBtn" style="padding: 0.5rem 1.5rem; font-size: 0.8rem;">Log In</button></nav>
</header>
<section class="hero">
<h1 style="font-family: var(--font-main); font-weight: 900; letter-spacing: -1px; text-transform: uppercase;">Calibrate Your Eye</h1>
<p style="text-transform: uppercase; letter-spacing: 1px; font-size: 0.9rem; font-weight: bold; color: #666;">Master Value. Mix Chroma. Replicate Form.</p>
</section>
<section class="module-box" id="module1">
<div class="module-sidebar">Module 01</div>
<div class="module-content">
<h2>Value Match</h2>
<div class="comparison-wrapper">
<div class="labels"><span>Target</span><span>Match</span></div>
<div class="comparison-board"><div class="swatch" id="targetValue"></div><div class="swatch" id="userValue"></div></div>
</div>
<div class="controls-wrapper">
<button type="button" class="icon-btn" id="btnMinus">-</button>
<div class="slider-group" style="margin-bottom: 0;"><input type="range" id="valueSlider" min="0" max="255" value="255"></div>
<button type="button" class="icon-btn" id="btnPlus">+</button>
</div>
<div class="btn-container">
<button type="button" class="btn" id="checkBtn">Verify Match</button>
<button type="button" class="btn btn-outline hidden" id="nextBtn">Next Challenge</button>
</div>
<div id="result" class="result-text"></div>
</div>
</section>
<section class="module-box" id="module3">
<div class="module-sidebar">Module 02</div>
<div class="module-content">
<h2>Color Theory</h2>
<div class="comparison-wrapper">
<div class="labels"><span>Target</span><span>Match</span></div>
<div class="comparison-board"><div class="swatch" id="targetChroma"></div><div class="swatch" id="userChroma"></div></div>
</div>
<div class="controls-wrapper" style="flex-direction: column; gap: 1rem; width: 100%;">
<div class="slider-group"><div class="slider-label">Hue</div><input type="range" id="hueSlider" min="0" max="360" value="0" style="background: linear-gradient(to right, #f00 0%, #ff0 17%, #0f0 33%, #0ff 50%, #00f 67%, #f0f 83%, #f00 100%);"></div>
<div class="slider-group"><div class="slider-label">Saturation</div><input type="range" id="satSlider" min="0" max="100" value="50"></div>
<div class="slider-group"><div class="slider-label">Lightness</div><input type="range" id="litSlider" min="0" max="100" value="50" style="background: linear-gradient(to right, #000, #fff);"></div>
</div>
<div class="btn-container">
<button type="button" class="btn" id="checkChromaBtn">Verify Mix</button>
<button type="button" class="btn btn-outline hidden" id="nextChromaBtn">Next Challenge</button>
</div>
<div id="chromaFeedback" class="feedback-stamp-container hidden">
<div class="stamp" id="stampHue">HUE <span class="stamp-icon" id="iconHue"></span></div>
<div class="stamp" id="stampSat">SAT <span class="stamp-icon" id="iconSat"></span></div>
<div class="stamp" id="stampLit">LGT <span class="stamp-icon" id="iconLit"></span></div>
</div>
<div id="chromaHint" class="hint-text hidden"></div>
<div id="chromaResult" class="result-text" style="margin-top: 1rem;"></div>
</div>
</section>
<section class="module-box" id="module2">
<div class="module-sidebar">Module 03</div>
<div class="module-content">
<h2>Spatial Drafting</h2>
<div class="procreate-workspace">
<div class="reference-cam-container">
<div class="reference-cam-label">Target Data</div>
<canvas id="targetPad" width="800" height="450" class="reference-canvas"></canvas>
</div>
<canvas id="drawPad" width="800" height="450" class="main-canvas"></canvas>
<div class="floating-toolbar">
<button class="tool-btn" id="toggleGridBtn" title="Toggle Grid Overlay">Grid</button>
<button class="tool-btn" id="toggleEraserBtn" title="Toggle Eraser">Eraser</button>
<button class="tool-btn" id="clearDrawBtn" title="Clear Canvas">Clear</button>
Hi all,
I am building a vanilla JS art calibration tool that requires users to identify the absolute lightest and darkest pixels in Old Master paintings.
The Problem: > I’m running a local server (python3 -m http.server), but I am constantly getting errors when calling ctx.getImageData().
What I’ve tried:
Setting img.crossOrigin = "anonymous"; before the src.
Using Wikimedia Commons direct URLs (which supposedly support CORS).
Cache-busting with Date.now() (this actually caused the host to reject the request).
Public CORS proxies (these get flagged by global firewalls/Jagex/Imperva).
It seems like browsers are inconsistently caching the images without the proper headers, leading to a permanent lock on the getImageData method.
The Question: Is there a way to force a 'Clean Pipe' for pixel-level access on CC0 images without building a dedicated Node.js backend proxy? Are there specific art-friendly CDNs that guarantee the Access-Control-Allow-Origin: *header for canvas manipulation?
