How to use the chroma key and color replacer
- Choose or drop an image. The edge color is picked automatically and the background disappears at once.
- Click the color you want to remove on the image and adjust tolerance and edge softness. To change a color, switch the action to Replace and pick a new color.
- If color remains at the edges, adjust Remove color spill and Shrink edge, then save as PNG.
How colors are removed and replaced
Chroma keying makes one color transparent so that another background can be placed behind. This tool measures how different each pixel is from the selected color and makes similar pixels more transparent. The difference is measured in the Lab color space, which is close to how people perceive differences, so shades of the same color with different brightness are handled more naturally.
Colors within the tolerance become fully transparent, and across the softness range outside it they become less and less transparent. This keeps blended areas such as hair and semi-transparent edges from being cut hard. Turning on the connected-area option protects parts inside the subject that have the same color as the background, such as clothing.
Photos shot on a green screen often have green spill around the edges. Remove color spill reduces the same-family component in pixels near the edge. Shrink edge pulls the transparent boundary a few pixels inward to remove a leftover rim. Replacing a color adds the shift from the selected color to the new color to each pixel, so brightness and texture are kept.
Ideas and limits
You can make the white background of a product photo transparent for a shop or design, or use a frame shot on a green screen as a source for compositing. It also helps to change only one color of a logo and make several color versions. Replacing colors is handy for comparing color options of clothes or props quickly.
Photos where the background and subject have similar colors, or with many shadows and reflections, may not come out clean in one pass. Lower the tolerance and turn on the connected-area option, or work in several passes. This tool looks only at color differences, so a professional editor is more accurate for complex backgrounds.
To change just one color on a small object photo, turn on the connected-area option and click the part to change. The same color elsewhere stays as it is. Replacing keeps shading, so it is handy for making several color options of a product and comparing them.
After removing a green background, change the preview background to magenta or black and check the edges. A green rim that was hard to see on the checkerboard shows on a dark background. Raising Remove color spill or Shrink edge by 1px usually cleans it up.
When you shoot, light the background evenly and keep the subject away from it, and the result is much cleaner. Wrinkles and shadows on the background create color differences and leave parts that do not disappear, so pull the cloth tight and light it evenly from the front.
If you want the effect on only part of an image, split the work in two passes. Remove the large background first and save, then upload that image again and remove the remaining color, so you can keep the tolerance low and still clean it up. This loses less detail of the subject than raising the tolerance a lot in one go.
Tips for clean results
- A photo with an evenly lit background that does not share colors with the subject works best.
- Start with a low tolerance and raise it little by little.
- If the inside of the subject disappears too, turn on the connected-area option.
- If color remains at the edge, raise Remove color spill first.
- Change the preview background to check that the result looks fine on other colors.
FAQ
Can I remove a background that is not green?
Yes. Any solid background such as white, blue or gray can be removed. Click the color to remove on the image, or pick it with the color picker, and adjust the tolerance. Busy photo backgrounds with many colors may not be removed cleanly.
What is the difference between tolerance and softness?
Colors within the tolerance are removed fully, and across the softness range beyond it they are removed less and less. Tolerance sets how wide the removed color range is, and softness sets how naturally the edge blends. If the edge looks rough, raise softness a little.
Green is left around the edges.
Raising Remove color spill reduces the green component in pixels near the edge. If some remains, raise Shrink edge to 1 or 2 pixels. Both options apply only when removing.
What happens to shading when I replace a color?
Replacing adds the difference between the selected color and the new color to each pixel, so brightness variation stays. Shading and texture are kept and the object does not look flatly painted. If the colors differ a lot, adjust the tolerance to match the area that changes.
Why use a color distance close to human vision?
Plain RGB differences do not match how people see color, so dark areas get removed too much and bright areas too little. This tool measures distance in the Lab color space, which is closer to human vision, so the tolerance applies more evenly.
Notes & limitations
This is a simple tool based on color differences and cannot cut out complex backgrounds perfectly. Images are processed only in the browser and are not sent to a server. Check portrait and copyright rights yourself.