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To use advanced options for removing digital noise
Edit workspace
1 Choose Adjust Digital Noise Removal.
The Digital Noise Removal dialog box appears.
Note: The three crosshairs appear on the image preview in the
Remove Noise tabbed area. The crosshairs represent noise samples
located in the image’s light, midtone, and dark areas. You can
move a crosshair by dragging the bounding box in the before
pane, which moves the sampling region accordingly.
2 In the Remove Noise tabbed area, mark the Link detail sizes check
box to adjust the Small, Medium, and Large settings in proportion
to each other.
3 Type or set values in the Small, Medium, and Large controls.
These controls define the amount of correction to apply to small,
medium, and large noise patterns.
4 Type or set a value in the Correction blend control to determine to
what degree the corrected image will be blended in with the
original.
The blending values range from 0.0 (no noise reduction) to 100.0
(full processing of the entire image). The default value is 70.
5 Type or set a value in the Sharpening control to determine the
degree of sharpening, if any, to apply to the image after the noise
reduction is applied.
The default value is 0.
6 Click OK.
You can also
Set corrections for light, midtone,
and dark areas independently
Unmark the Link detail sizes check
box, and type or set values in the
Small, Medium, and Large controls.
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You can have a maximum of 10 sampling regions.
You should avoid sampling an image edge, or pure black or
pure white regions of the image, which can result in excessive
smoothing.
The Digital Noise Removal command is not designed to remove
moire patterns. For information about removing moire
patterns, see “To remove moire patterns” on page 218.
To save settings as a preset specific to an image and camera,
mark the Camera preset check box and click the Save Preset
button
. When the Camera preset check box is marked, the
Load Preset drop-list displays only previously saved camera
presets, not the standard presets. To save settings as a standard
preset, unmark the Camera preset check box, and click the Save
Preset button.
For best results when working with JPEG images, choose Adjust
Add/Remove Noise JPEG Artifact Removal before using the
Adjust Digital Noise Removal command.
To protect image areas from noise corrections
Edit workspace
1 Choose Adjust Digital Noise Removal.
The Digital Noise Removal dialog box appears.
View close-ups of sampling regions Click a crosshair to see the area close
up in the Before and After panes.
Add a sampling region crosshair
Drag in the Before pane.
Delete a sampling region crosshair In the Before pane, drag a corner of
the correction box to its diagonally
opposite corner.
You can also
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2 Click the Protect Image tab.
3 In the Before pane, pan and zoom as necessary so that you can
view the region you want to protect.
4 Hold down Ctrl, and drag over the region you want to protect.
Note: Holding down Ctrl does not create a corresponding
crosshair in the image window of the Remove Noise tabbed area.
5 In the Selected hue range group box, type or set values in the Hue
and Range controls.
Note: The existing settings reflect the area sampled. You can
manually adjust the hue knob by dragging it inside the ring.
6 In the Protect selected hue range group box, drag any of the
seven graph handles downward to apply less correction and
smoothing to the corresponding segment of the hue range.
For example, dragging just the middle graph handle to the
bottom of the graph completely suppresses the midtone of that
hue range.
Note: The graph handles cannot be dragged laterally.
7 Click OK.
You can remove color adjustments for a selected color range by
clicking Reset Current. To remove all color adjustments, click
Reset All.
Removing chromatic aberrations
Chromatic aberration occurs when the camera records incorrect colors
within the image. In conventional film cameras, chromatic aberration
is usually caused by a lens defect. In digital cameras, several factors can
contribute to chromatic aberration, including the following:
• The inherent lens aberration in the camera may cause fuzziness at
image edges. Photos taken with telephoto and zoom lenses are
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more prone to contain chromatic aberrations because of the way
in which digital cameras capture light rays far from the optical
axis.
• The auto-exposure feature of the camera, which estimates the
correct exposure setting, may cause sensor blooming.
• Different colors may be caught by different camera sensor
elements, and they may combine to make one pixel. This process
is called demosaicing.
• Activities such as artifact removal, noise removal, and sharpening
may occur inside the camera after processing.
In your own digital photos, you may notice chromatic aberrations in
photos with the following content:
• the sky seen through tree branches or leaves
• the edges of interior doors or windows through which bright light
enters
• fireworks or city lights
• fluorescent light fixtures or bare lightbulbs
• sun or light reflections on water
• reflections on chrome
• the edges of backlit objects
• sunlit white shirts against a dark background
After identifying these types of color defects, you can reduce or
eliminate them.
To remove chromatic aberrations from a photo
Edit workspace
1 Choose Adjust Chromatic Aberration Removal.
The Chromatic Aberration Correction dialog box appears.
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2 Ensure that the Before and After panes are visible at the top of the
dialog box.
3 Set the zoom control in the dialog box to at least 200%.
The zoom control is located below the Before and After panes.
Zooming to 200% helps target the problem areas in the photo.
4 Click the Pan button , and pan the image to set a viewable
image area in the Before pane.
5 In the Before pane, drag to define the area needing correction.
Note: The area needing correction is called the sample box. You
can create up to 10 sample boxes. Each sample box is represented
as “Sample
n
” (where
n
is a number from 1 to 10) in the List of
Samples area in the center of the dialog box. Each sample listing
has a color swatch to the left, indicating a color average for the
sampled area.
6 Choose a sample entry from the List of Samples area.
7 Type or set a value in the Range control to determine the color
range of the active sample, which affects the pixel range to be
corrected.
The range you specify is represented in the color box directly
above the Range control.
8 Type or set a value in the Radius control to determine the size of
the sample’s aberration.
Note: The default value is 10. Values from 4 to 20 usually
produce the most acceptable results. Values greater than 10 are
useful on sampling areas that enclose sensor blooming
aberrations. Values less than 10 are useful when you are removing
1- or 2-pixel aberrations caused by demosaicing, as well as when
you are working on images of less than one megapixel. Set the
Radius control to the smallest setting that effectively removes the
aberration.
9 Click OK.
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To create more than 10 sample boxes, you can apply the
corrections and then restart the effect.
You can automatically create a new layer on which the
corrected image resides by marking the Result on New Layer
check box. This option protects your original image on its own
layer. If you do not mark this check box, the corrections are
applied on the same layer as the original image.
You can limit the number of “false corrections” by making a
selection and then marking the Result on New Layer check box.
You can also use this command on separate layers of an image.
You can also
Resize a sample box
Drag a sample box handle.
Delete a sample box button in the
dialog box
Click a sample box, and click
Remove.
Delete a sample box
Drag a corner onto its diagonally
opposite corner, and stop dragging
when the corners meet.
Display the affected image areas
Mark the Show Differences check
box. The affected areas appear in the
After pane as white areas on black.
Brighter areas represent greater
degrees of correction.
Preview the results on the image
Mark the Show Differences check
box, and make sure the Preview on
Image check box is marked.
Documents you may be interested
Documents you may be interested
