Adobe photoshop elements Manual Do Utilizador
CHAPTER 9
206
Applying Filters and Effects
Other filters
Filters in the Other submenu let you create your
own filter effects, use filters to modify masks, offset
a selection within an image, and make quick color
adjustments.
own filter effects, use filters to modify masks, offset
a selection within an image, and make quick color
adjustments.
Custom
Lets you design your own filter effect.
With the Custom filter, you can change the
brightness values of each pixel in the image
according to a predefined mathematical operation
known as convolution. Each pixel is reassigned a
value based on the values of surrounding pixels.
brightness values of each pixel in the image
according to a predefined mathematical operation
known as convolution. Each pixel is reassigned a
value based on the values of surrounding pixels.
You can save the custom filters you create and use
them with other Photoshop images.
them with other Photoshop images.
To apply a Custom filter effect:
1
Choose Filter > Other > Custom, or use the
Filters palette to apply the Custom filter.
2
Select the center text box, which represents the
pixel being evaluated. Enter the value by which
you want to multiply that pixel’s brightness value,
from –999 to +999.
you want to multiply that pixel’s brightness value,
from –999 to +999.
3
Select a text box representing an adjacent pixel.
Enter the value by which you want the pixel in this
position multiplied.
position multiplied.
For example, to multiply the brightness value of
the pixel to the immediate right of the current
pixel by 2, enter 2 in the text box to the immediate
right of the center text box.
the pixel to the immediate right of the current
pixel by 2, enter 2 in the text box to the immediate
right of the center text box.
Note: To avoid turning the image completely white
or black, the sum of the values in the matrix should
equal 1.
or black, the sum of the values in the matrix should
equal 1.
4
Repeat steps 2 and 3 for all pixels to include in
the operation. You don’t have to enter values in all
the text boxes.
the text boxes.
5
For Scale, enter the value by which to divide the
sum of the brightness values of the pixels included
in the calculation.
in the calculation.
6
For Offset, enter the value to be added to the
result of the scale calculation.
7
Click OK. The custom filter is applied to each
pixel in the image, one at a time.
Use the Save and Load buttons to save and reuse
custom filters.
custom filters.
DitherBox
™
Creates a custom dither pattern for a
selected RGB color. (See “Creating and applying
custom dither patterns” on page 237.)
custom dither patterns” on page 237.)
High Pass
Retains edge details in the specified
radius where sharp color transitions occur and
suppresses the rest of the image. (A radius of 0.1
pixel keeps only edge pixels.) The filter removes
low-frequency detail in an image and has an effect
opposite to that of the Gaussian Blur filter.
suppresses the rest of the image. (A radius of 0.1
pixel keeps only edge pixels.) The filter removes
low-frequency detail in an image and has an effect
opposite to that of the Gaussian Blur filter.
It is helpful to apply the High Pass filter to a
continuous-tone image before using Image >
Adjustment > Threshold or converting the image
to Bitmap mode. The filter is useful for extracting
line art and large black-and-white areas from
scanned images.
continuous-tone image before using Image >
Adjustment > Threshold or converting the image
to Bitmap mode. The filter is useful for extracting
line art and large black-and-white areas from
scanned images.
Minimum and Maximum
Are useful for modifying
masks. The Minimum filter has the effect of
applying a spread—spreading out black areas and
shrinking white areas. The Maximum filter has the
effect of applying a choke—spreading out white
areas and choking in black areas. Like the Median
filter, the Maximum and Minimum filters look at
applying a spread—spreading out black areas and
shrinking white areas. The Maximum filter has the
effect of applying a choke—spreading out white
areas and choking in black areas. Like the Median
filter, the Maximum and Minimum filters look at