User's Manual

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ADOBE PHOTOSHOP CS2
User Guide
See also
“About High Dynamic Range images” on page 201
Converting between color modes
Converting an image to another mode
You can change an image from its original mode (source mode) to a different mode (target mode). When you choose
a different color mode for an image, you permanently change the color values in the image. For example, when you
convert an RGB image to CMYK mode, RGB color values outside the CMYK gamut (defined by the CMYK working
space setting in the Color Settings dialog box) are adjusted to fall within gamut. As a result, some image data may be
lost and can’t be recovered if you convert the image from CMYK back to RGB.
Before converting images, it’s best to do the following:
• Do as much editing as possible in the original image mode (usually RGB for images from most scanners or digital
cameras, or CMYK for images from traditional drum scanners or imported from a Scitex system).
• Save abackupcopybeforeconverting. Be sure to save acopyofyourimage that includes alllayerssothatyou can
edit the original version of the image after the conversion.
• Flatten the file before converting it. The interaction of colors between layer blending modes changes when the
mode changes.
To convert an image to another mode
❖ Choose Image > Mode andthe mode youwantfromthe submenu. Modesnot availablefor theactiveimage appear
dimmed in the menu.
Images are flattened when converted to Multichannel, Bitmap, or Indexed Color mode, because these modes do not
s
upport layers.
Making a conditional mode change
You can specify conditions for a mode change so that the conversion can occur during an action,which is aseriesof
commands appliedsequentiallytoasingle file or abatch of files. When amodechangeispartofanaction, 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
t
he source mode and a mode for the target mode.
To add a conditional mode change to an action
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. You can also use the
All or None buttons to select all possible modes or no mode.