Erase Every Other Row
Erase Every Other Row is similar
to the Deinterlace filter, but, instead of interpolating the erased
row with the surrounding ones, it replaces the erased row with
transparency or with the background color.Erase Every Other Row can also operate on vertical stripes.
The Erase Every Other Row dialog is simple. Choose between rows and
columns, between even or odd, and between transparency (erase) or the
background color (fill)--unless the layer
lacks an Alpha channel, in which case the only
option is the background color.
Video
Video simulates the distortions that can occur in an image that was
captured with a video camera.
The dialog is unusual, since the preview of the various video patterns is displayed on a fixed image of a fox, rather than on the image being transformed.
Additive adds the pattern to the image; otherwise it's
subtracted.
Rotated rotates the pattern by 90 degrees.
To see the effects of the various video patterns, click through them
in the dialog. The Figure shows the result of
applying a Wide-striped Video Pattern to Figure 2.33.
Xach-Effect
The Xach-Effect filter adds a translucent 3D effect to a selection or
Alpha channel. We created a rectangular selection in the image. The Xach-Effect filter works by
detaching the selection from the image and moving it by the
Highlight offset amount specified in the dialog. The
Highlight color appears
around the detached selection, and its
Highlight Opacity is an
Alpha value in [0 to 255], which means the default of 66 is
equivalent to 26\%. The last three fields specify the drop shadow parameters, just like in the Drop Shadow filter.
Finally, if the
Keep selection box is checked, the
selection remains after the filter is run.
Blinds
The Blinds filter simulates the effect of blinds in front of the
image. The effect of Blinds is demonstrated on the image of Figure 17.53. You can choose the orientation of the
blind blades, their width (called
Displacement), and their
number. The blinds can be the current Background color or Transparent.
Predator
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The Predator dialog does not
include a preview. The filter uses an edge-detect algorithm, and
Edge amount in [0 to 24] changes the sensitivity of the edge
detection. If
Pixelize is checked, the filter applies
pixelization to the result. Set the amount of pixelization via
Pixel amount in [1 to 16]. If
Keep selection is
checked, the filter is applied to the current selection, and if not,
it's applied to the current layer. If
Separate layer is
checked, the filter leaves the original layer untouched and creates a
new layer.
Slide
The Slide filter requires an RGB image with only one layer.
It builds a color transparency with border and holes and crops or
resizes the image so its proportions are 3:2, which are the
proportions of a 32~mm slide.
The Slide dialog allows you to
input text that is printed in the slide borders and number of the
slide and choose the font family and the font color. As with the
preceding filters, a checkbox allows you to create a new image instead
of changing the original.
Filmstrip
The Filmstrip filter simulates a strip of
positive photographic film (remember those?) with one or more
photographs. Before choosing the filter, open the target images in GIMP. In the
Image Selection area of the dialog, the left column shows the images that
are open, and the right column shows the images that will be included
in the film. Add an image to the right column by selecting it in the
left column and clicking
+Add. Conversely, remove an image
from the right column by clicking its name and then
-Remove.
The
Height of the resulting images can be set in the
corresponding field or will be determined based on the images used if
the
Fit height to images box is checked. The
Color
will be the color of the film surrounding the images. Images are
numbered in the film, according to the adjustable parameters:
Start index,
Font,
Color, and position in the
film (
At top or
At bottom).
The Advanced tab, not shown here, allows you to change the sizes of
all the components of the simulation relative to the image size. The
default values have been computed to simulate a filmstrip correctly,
making adjustments on the Advanced tab generally leads to strange and
unnatural results.
Stencil Carve
Stencil Carve uses a grayscale source image as a
stencil to carve a design into a target image of the same size. The
source image must have only one layer without an Alpha
channel, otherwise the filter name is grayed out
in the Decor menu. The Stencil Carve dialog contains only two parameters: a menu to select the target image and a
checkbox to select
Carve White Areas. If the box is unchecked,
the inverse of the source image is used as the stencil. A possible result is shown here. The source
image was a grayscale copy of the target image.
Stencil Chrome
Stencil Chrome also requires a grayscale image
without an Alpha channel. This filter uses an
environment map as a stencil to add a chrome effect to the source
image. The figure shows the result of applying the Stencil
Chrome filter with a spiral gradient. The environment map is also a
grayscale image, which has to be the same size as the
original. Rather than selecting an image open in GIMP, you can choose
the environment map from anywhere on your drive. The various
parameters are rather self-explanatory. This filter is rather
unstable, however, which means that from time to time it crashes. Be
sure to save your image before working with it.
Fog
Fog creates a new layer above the current layer in the image, and adds a semi-transparent fog.
The dialog contains only four parameters: the name of the new layer, the color of the fog (the default color produces a sulfurous, cough-inducing smoke), its
turbulence [1 to 10] and its opacity.
