Adobe 65045315 - Photoshop Elements Use Manual page 195

USING PHOTOSHOP ELEMENTS 10
Understanding color
Note: Hidden layers are discarded and images are flattened automatically when you convert them into bitmap or
indexed-color mode, because these modes do not support layers.
The default mode of new Photoshop Elements images and images from your digital camera. In RGB
RGB Color mode
mode, the red, green, and blue components are each assigned an intensity value for every pixel—ranging from 0 (black)
to 255 (white). For example, a bright red color might have an R value of 246, a G value of 20, and a B value of 50. When
the values of all three components are equal, the result is a shade of neutral gray. When the value of all components is
255, the result is pure white; when the value is 0, the result is pure black.
Convert an image to bitmap mode
To convert an image to bitmap mode, you must first convert it to grayscale mode, simplifying the color information
in the image and reducing its file size. Converting to grayscale removes the hue and saturation information from the
pixels and leaves just the brightness values. However, because few editing options are available for bitmap-mode
images, it's usually best to edit the image in grayscale mode and then convert it.
1 Choose Image > Mode > Bitmap.
If the image is RGB, click OK to convert it to grayscale.
2
3 For Output, enter a value for the output resolution of the bitmap-mode image, and choose a unit of measurement.
By default, the current image resolution appears as both the input and the output resolutions.
4 Select one of the following bitmap conversion methods, and click OK:
Converts pixels with gray values above the middle gray level (128) to white, and those below to black.
50% Threshold
The result is a very high-contrast, black-and-white representation of the image.
Original grayscale image (left) and 50% Threshold conversion method applied (right).
Converts an image by organizing the gray levels into geometric configurations of black and white dots.
Pattern Dither
Converts an image by using an error-diffusion process, starting at the pixel in the upper-left corner
Diffusion Dither
of the image. If the pixel's value is above middle gray (128), the pixel is changed to white—if it's below middle gray, it's
changed to black. Because the original pixel is rarely pure white or pure black, error is inevitably introduced. This error
is transferred to surrounding pixels and diffused throughout the image, resulting in a grainy, film-like texture. This
option is useful for viewing images on a black-and-white screen.
Pattern Dither and Diffusion Dither conversion methods
Last updated 1/2/2012
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