Adobe Photoshop CS3 - Manual (Page 120)

PHOTOSHOP CS3
User Guide
113
Add a conditional mode change to an action
You can specify conditions for a mode change so that the conversion can occur during an action, which is a series of
commands applied sequentially to a single file or a batch of files. When a mode change is part of an action, an error
can occur if the file being opened is not in the source mode specified in the action. For example, suppose one step
in an action is to convert an image with a source mode of RGB to a target mode of CMYK. Applying this action to
an image in Grayscale mode, or any other source mode besides RGB, results in an error.
When you record an action, you can use the Conditional Mode Change command to specify one or more modes for
the source mode and a mode for the target mode.
1 Start recording an action.
2 Choose File > Automate > Conditional Mode Change.
3 In the Conditional Mode Change dialog box, select one or more modes for the source mode. Use the All or None
buttons to select all possible modes or no mode.
4 Choose a target mode from the Mode pop-up menu.
5 Click OK. The conditional mode change appears as a new step in the Actions palette.
See also
“Automating with actions” on page 610
Convert a color photo to Grayscale mode
1 Open the photo you want to convert to black-and-white.
2 Choose Image > Mode > Grayscale.
3 If asked to discard color info, click OK. Photoshop converts the colors in the image to black, white, and shades of gray.
See also
“Convert a color image to black and white” on page 170
Convert an image to Bitmap mode
Converting an image to Bitmap mode reduces the image to two colors, greatly simplifying the color information in
the image and reducing its file size.
When converting a color image to Bitmap mode, first convert it to Grayscale mode. This removes the hue and
saturation information from the pixels and leaves just the brightness values. However, because only a few editing
options are available for Bitmap mode images, it’s usually best to edit the image in Grayscale mode and then convert
it to Bitmap mode.
Note: Images in Bitmap mode are 1 bit per channel. You must convert a 16- or 32-bits-per-channel image to 8-bit
Grayscale mode before converting it to Bitmap mode.
1 Do one of the following:
• If the image is in color, choose Image > Mode > Grayscale. Then choose Image > Mode > Bitmap.
• If the image is grayscale, choose Image > Mode > Bitmap.
2 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.