Section III Digital Postprocessing
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a converter with their cameras, as well. The major
areas of adjustment are exposure, white balance,
and contrast, Figure 15-6.
Cropping and Resizing Images
To bring out the best in an image, cropping
is often necessary. For those who scan their own
images, cropping is often performed as part of
the scanning process. Images from a CD, or those
imported directly from a digital camera, will be
full-size—any cropping will need to be done with
the image editing software.
The
Rectangular Marquee
tool can be used to
crop an image, Figure 15-7. After using a mouse
click to highlight the tool on the toolbox, the user
then clicks on one of the intended corners of the
area to be cropped. By holding down the mouse
button and dragging the cursor to the diagonally
opposite corner, a rectangular frame of dashed
lines will be visible. When the mouse button is
released, the lines of the frame will appear to
be in motion (this appearance is referred to by
veteran Photoshop users as “the marching ants.”).
The border can be moved by clicking inside it and
dragging the frame in the desired direction. It
cannot be changed in size, however. If a different-
size crop is needed, click outside the frame to
delete it, and then repeat the click-and-drag
process to create a new frame. To perform the
actual crop, select
Crop
from the
Image
dropdown
menu.
A more flexible method is the use of the
Cropping
tool. Grouped with the selection
marquees on the toolbox, this tool is applied
in the same way (click and drag), but can be
Figure 15-6. RAW converter software is used to make adjustments to a RAW capture
before saving it as a file that can be used with Photoshop or other image processing
software. A color histogram provides a dynamic display as exposure, contrast, or other
values are adjusted. One very useful feature of the RAW converter is the ability to alter
the color temperature (white balance) of the image to correct color casts or to simulate
the effects of warming or cooling filters.
Histogram
White balance menu/
color temperature slides
Image adjustment sliders
Figure 15-7. Clicking and dragging create a frame
(“rectangular marquee”) to identify the desired crop.
The frame can be moved, but not adjusted in size. If a
different crop is desired, the frame is deleted and a new
one created with the mouse.