Resizes the image to a specified width and height using a
specified interpolation method.
The interpolation parameter should be viewed as a request rather
than a command because not all types of interpolation can be used
on all types of image. If the method you specify is not appropriate
then ABCpdf will automatically select a suitable alternative.
After an image has been resized it is no longer compressed. You
may wish to compress it using the StreamObject.Compress
method.
The Interpolation enumeration may take the following values:
- Auto
- NearestNeighbor
- Linear
- Cubic
- Super
- Lanczos
The Auto setting allows ABCpdf to automatically choose an
appropriate interpolation algorithm given the type of image and the
type of scaling. If you are aiming to maximize quality this is the
setting you should use.
The nearest neighbor algorithm is the fastest but also the
lowest quality method. It simply finds the nearest pixel in the
source image and maps it through to the destination image. However
it is also the only method which can be used for Indexed color
images.
The Linear, Cubic and Lanzcos methods are progressively higher
quality methods based around a weighted average of pixels from the
source image. However they are also progressively slower. The
Lanzcos function used is the three lobed variety.
The Linear, Cubic and Lanzcos methods use weighted averages from
a limited number of pixels in the source image. For large size
reductions this may result in information from some pixels in the
source image being completely discarded. The super method aims to
work around this issue by increasing coverage to all the pixels in
the source image. It only works if an image is being reduced in
both height and width.
This function is optimized for resizing one, three and four
component images at precisions of eight or sixteen bits per
component.
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