Pixelate Filters - Adobe PHOTOSHOP ELEMENTS Manual

CHAPTER 9
200
Applying Filters and Effects
Despeckle
where significant color changes occur) and blurs
all of the selection except those edges. This blur-
ring removes noise while preserving detail.
Dust & Scratches
dissimilar pixels. To achieve a balance between
sharpening the image and hiding defects,
try various combinations of radius and threshold
settings. Or apply the filter on selected areas in
the image.
To use the Dust & Scratches filter:
1 Choose Filter > Noise > Dust & Scratches, or
use the Filters palette to apply the Dust & Scratches
filter.
2 If necessary, adjust the preview zoom ratio until
the area containing noise is visible.
3 Drag the Threshold slider left to 0 to turn off the
value, so that all pixels in the selection or image
can be examined.
The Threshold determines how different the
pixels' values should be before they are eliminated.
Note: The Threshold slider gives greater control for
values between 0 and 128—the most common range
for images—than for values between 128 and 255.
Drag the Radius slider left or right, or enter a
4
value in the text box from 1 to 100 pixels. The
radius determines how far the filter searches for
differences among pixels.
Adjusting the radius makes the image blurry. Stop
at the smallest value that eliminates the defects.
Detects the edges in an image (areas
Reduces noise by changing
5 Increase the threshold gradually by entering a
value or by dragging the slider to the highest value
possible that eliminates defects.
6 Click OK.
Reduces noise in an image by blending
Median
the brightness of pixels within a selection.
The filter searches the radius of a pixel selection
for pixels of similar brightness, discarding pixels
that differ too much from adjacent pixels, and
replaces the center pixel with the median
brightness value of the searched pixels. This filter
is useful for eliminating or reducing the effect of
motion on an image.
Pixelate filters
The filters in the Pixelate submenu sharply define
a selection by clumping pixels of similar color
values in cells.
Simulates the effect of using an
Color Halftone
enlarged halftone screen on the image. The filter
divides the image into rectangles and replaces each
rectangle with a circle. The circle size is propor-
tional to the brightness of the rectangle.
To use the Color Halftone filter:
Choose Filter > Pixelate > Color Halftone,
1
or use the Filters palette to apply the Color
Halftone filter.
Enter a value in pixels for the maximum radius
2
of a halftone dot, from 4 to 127.
Enter a screen-angle value (the angle of the
3
dot from the true horizontal) for one or
more channels: