Image Histogram

Visualize RGB and luminance histograms of any image. Analyze color distribution and exposure levels — 100% client-side.

Histogram Analyzer
Original (A)
Drop or click to load image
Comparison (B)
Drop or click to load image
🛡️Zero server logs. Histogram computation runs 100% inside your browser. Your files never leave this tab.
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Image Histogram

Image Histogram computes RGB channel and luminance histograms for any image. All processing happens locally via Web Workers.

🔒 Client-side only⚡ Web Worker processing🌐 Works offline🛡️ Zero server logs

How to Use Image Histogram

  1. Drag and drop an image or click to select from your device.
  2. Click Analyze to compute the histogram data.
  3. View the RGB and luminance distribution charts for detailed analysis.

Frequently Asked Questions

Got questions about image histograms?

What is an image histogram?

An image histogram shows the distribution of pixel intensities across an image. It helps analyze exposure, contrast, and color balance.

What do the RGB channels show?

Each channel (Red, Green, Blue) shows the intensity distribution for that color component. Peaks on the left indicate darker areas, while peaks on the right indicate brighter areas.

Is my image data private?

Yes, absolutely. All processing runs in your browser via Web Workers. Your images never leave your device.

Automated E2E Test Suite Logs

Our build systems validate edge-case processing under extreme conditions before each deployment.

Stability
100.0%
Passed
9/9
Env
V8-Sandbox
Engine: Vitest RunnerUpdated: 2026/7/13 03:02:43📦 Download Test Datasets
PASSPure Function Unit Tests should handle valid image input
PASSPure Function Unit Tests should reject invalid input
PASSPure Function Unit Tests should not mutate original input
PASSPure Function Unit Tests should handle boundary input
PASSImageHistogramTool renders labels
PASSImageHistogramTool renders privacy strip
PASSImageHistogramTool shows Clear All when image loaded
PASSImage Worker — IPC Simulation should return ok:true with histogram result for valid action
PASSImage Worker — IPC Simulation should return ok:false with error for unknown action
⏱️ 0.18ms📦 1.5KB🎚️ Max Nesting: 3🌿 AST Nodes: 48🛡️ V8 Heap: Healthy
$ codecaven-validator --scope=tool● CLUSTER COMPLIANT

Tool Changelog & Updates

v1.2.02026-06-12
  • Feature: Dual-image comparison mode — upload two images side by side with overlapping histogram overlays.
  • Feature: MSE (Mean Squared Error) metric per channel — quantifies histogram deviation between original and comparison images.
  • UX: Unified scale for both histograms ensures accurate visual comparison.
  • Performance: Optimized histogram computation with Uint32Array arrays.
v1.1.02026-06-11
  • Feature: Added comprehensive Vitest test suite covering Tool rendering, worker operations, and shared operation logic — all 871 image tests passing.
  • Fix: Fixed OffscreenCanvas mock patterns in tests for proper constructor instantiation.
v1.0.02026-06-11
  • Feature: Initial release with RGB and luminance histogram visualization — 100% client-side via Web Worker.
  • UX: Drag-and-drop upload with instant preview and 4-channel histogram display (R, G, B, Luminance).
  • UX: 16-bin aggregation for clear, readable bar charts without external chart libraries.