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Posterization is the process of reducing the number of colors to a manageable level so the image can be vectorized.

  1. Choose the posterization method you want.
  2. Choose the number of colors.
  3. Click Posterize.

    After the bitmap is posterized, the resulting colors will be displayed in the dialog box.

    Your software provides three methods of posterization:

    Fast Posterization

    This method works on each of the three color channels (Red, Green and Blue) separately. It divides the color range within each channel into equal bands, and then fits each pixel in the image to the color band closest to it.

    In this method you specify how many colors you want in the posterized results. Your software offers you a choice from a list of numbers: 8, 27, etc. If, for example, you want to divide each color channel into two bands, the total number of possible colors in all three channels will be 8 (2x2x2). In the same way, 3 bands per channel will create 27 colors (3x3x3), etc.

    The Fast method is the fastest posterization method. This method is useful for posterizing logos with very distinct colors. It is not recommended for photos because the colors in the posterized image are quite different than those in the original image.

    Smart Posterization

    In this method the program finds the most dominant colors in the image. Any pixel is converted to one of these dominant colors, the one closest to it in color. In this method you specify how many colors you want in the posterized result. This method is slower, but the results are much better than the Fast method.

    This method is recommended both for scanned logos and for photos. The limitation of this method is that if you have a picture with many background colors, such as many shades of blue in the sky, the program may prefer those to objects in the foreground.

    Manual Posterization

    In this method you not only decide how many colors you want, but you actually pick these colors in the image. When you choose the Manual method, the cursor changes to a pipette tool. Click the colors in the image you want in the final results. Any color you click on is added to the color list in the dialog box. If you picked a color by mistake, you can select this color in the dialog box and press the Delete key to remove it from the list.

See Also

Using Color Vectorization

Merging Colors