Image Color Histogram

Image Color Histogram

A histogram plots how many pixels fall at each brightness level, from black on the left to white on the right. It's the single most useful chart in photography for judging exposure and contrast objectively, instead of trusting a screen that might be too bright or too dim. This viewer draws a separate curve for the red, green, and blue channels, plus an overall luminance line.

Reading it is quick once you know the shape. A bunch of pixels piled against the left edge means crushed shadows (lost detail in the dark areas); piled against the right edge means blown highlights. A well-balanced photo usually spreads across the range without large spikes jammed at either end — though creative images break that rule all the time.

The per-channel view also reveals color casts. If the red curve sits well to the right of the others, the image skews warm; a raised blue curve skews cool. That makes the histogram a fast sanity check before you grade or correct a photo.

How to view an image histogram

1. Add your image — drag & drop, paste, or choose a file.
2. Read the curves — red, green, and blue channels plus a luminance line.
3. Judge the tones — check for clipping in the shadows or highlights.

Tip: watch the edges for clipping

Tall spikes hard against the far left or far right edge usually mean detail has been clipped to pure black or pure white. If you're editing, that's the first thing to pull back — once a channel is clipped, the information there can't be recovered.