Submenu Color Mode

Main Menu: Image > Color Mode

The color mode for each image can be changed, by using the commands in this submenu. The color mode determines what color method is used to display and print the image you’re working on.

Color modes determine the number of colors, and the file size of an image. Choosing a color mode also determines which tools and file formats are available.

The supported Color modes, as shown in the Color Mode menu are:

Color modes

Number of colors

Bits per pixel (bit depth)

Black & White

2 (black & white

1

Grayscale

256 shades of gray

8

Indexed 16 Colors

16 colors

4

Indexed 256 Colors

256 colors

8

RGB Color

16.7 million colors

24

Scanners usually produce Black & White, Grayscale or RGB Color image files. Digital cameras normally produce RGB Color files.

Some Medical Images may have channels with 16 bits per pixel, but the Color Mode submenu is not available then working on Medical Images because they are read only files.

Besides the image file type selected for saving an image, the Color mode influences, not only how the image look but its size in disk.

Black & White mode uses one of two color values (black or white) to represent the pixels in an image. These kind of images are also called bitmapped 1 bit images because they have a bit depth of 1.*

Grayscale mode uses different shades of gray in an image. There can be up to 256 shades of gray. Every pixel of a grayscale image has a brightness value ranging from 0 (black) to 255 (white).

Indexed Color mode produces 4 or 8 bit image files with 16 or 256 colors. When converting to indexed color, Bersoft Image Measurement builds a color palette, which stores and indexes the colors in the image. If a color in the original image does not appear in the table, the program chooses the closest one or uses dithering to simulate the color using available colors.

Because the palette of colors is limited, indexed color can greatly reduce file size yet maintain the visual quality when the original image has a limited number of colors.*

RGB Color mode uses the RGB model, assigning an intensity value to each pixel. The intensity values range from 0 (black) to 255 (white) for each of the RGB (red, green, blue) components in a color image.

RGB images use three colors, or channels, to reproduce colors on-screen. The three channels translate to 24 (8 bits x 3 channels) bits of color information per pixel. Up to 16.7 million colors can be reproduced. This is the normal color mode for color images and also the one that use more disk space when saving.

On the bottom of the Color Mode there is located the Color Table menu, which will be enabled only when indexed color images are used.

The color table allow loading and saving different color tables as well as adjusting the Color Table colors.

* Limited editing is available in this mode. Transform the image to RGB mode for edition when some feature is unavailable.