Autotek autocad raster design 2010 ユーザーズマニュアル
Contrast
You can move the slider to the right to decrease the tonal gradation or to
the left to increase the tonal gradation between the highlights, midtones,
and shadows in an image.
When contrast is increased to an extreme in a grayscale image, the shades
of gray can be polarized to just black and white. In a color image, an extreme
increase in contrast causes the selected color channel to become more
prominent. For example, if the selected color channel is red, then more
shades of red appear in the image.
the left to increase the tonal gradation between the highlights, midtones,
and shadows in an image.
When contrast is increased to an extreme in a grayscale image, the shades
of gray can be polarized to just black and white. In a color image, an extreme
increase in contrast causes the selected color channel to become more
prominent. For example, if the selected color channel is red, then more
shades of red appear in the image.
RGB
Specifies the color channel to change in a color image. For a grayscale image,
you can change only RGB, which represents the gray channel.
you can change only RGB, which represents the gray channel.
Index
Displays an index for a shade of the color channel that is currently selected.
When you place your pointer over a bar in the histogram, the Index value
displays the intensity of the shade that the bar represents (0 to 255).
When you place your pointer over a bar in the histogram, the Index value
displays the intensity of the shade that the bar represents (0 to 255).
Freq
Display a frequency value for a shade of the color channel that is currently
selected.
When you place your pointer over a bar in the histogram, the Freq value
displays the number of pixels in the image that are the shade that the bar
represents.
If you selected a grayscale image, then this value represents the number of
pixels that are the shade that corresponds to the bar.
If you selected a color image, and you choose a color channel, then the
frequency value represents the number of pixels that are the shade of the
selected color channel.
selected.
When you place your pointer over a bar in the histogram, the Freq value
displays the number of pixels in the image that are the shade that the bar
represents.
If you selected a grayscale image, then this value represents the number of
pixels that are the shade that corresponds to the bar.
If you selected a color image, and you choose a color channel, then the
frequency value represents the number of pixels that are the shade of the
selected color channel.
Apply Changes To
■
Entire Image. Applies the changes to the selected image.
■
Sub-Region. Applies the changes to the sub-region only.
Sub-Region Options
Displays palette options for sub-regions associated with an
(page 391) image:
■
Retain Current Palette. Applies your changes to the sub-region by
mapping to the closest colors from the current palette. This option
maintains the current palette and does not affect pixels outside the
selected region.
mapping to the closest colors from the current palette. This option
maintains the current palette and does not affect pixels outside the
selected region.
Brightness/Contrast Tab (Histogram Dialog Box) | 317