Image Color Tools
Adjust brightness, contrast, channels, and bit planes to surface low-contrast or hidden marks in an image.
Puzzle setters often hide a mark in a picture by drawing it in a color almost identical to the background, or by tucking it into the lowest bits of each pixel. Load an image below, then push the controls until the hidden detail pops. Every adjustment is recomputed from the original, so you can stack and undo freely without losing quality.
Adjustments
Geometry
Load an image to begin. Adjustments apply live.
How it works
Each adjustment runs over the original pixels, so nothing is lost when you stack several together or pull a slider back. Color and tone changes happen first at the pixel level, then any flip, rotate, or stretch is applied as the result is drawn to the output canvas.
Two views are especially good at surfacing hidden marks. Threshold forces every pixel to pure black or white at a brightness cutoff you choose, which exposes a faint shape drawn just a shade off the background. The bit-plane view shows a single bit of each pixel as black or white. The lowest bit holds detail the eye never sees, so a message tucked into those bits often appears as readable text or a picture there.
Channel isolation looks at one color channel at a time, handy when a mark was drawn in just the red, green, or blue layer. Pair these with high contrast, invert, or a hue rotation to pull weak detail out of a busy background.