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Bitmap scaling

You can scale bitmap images by using the Bitmap.scaleInto() method that is provided in the

net.rim.device.api.system package. The method creates a scaled copy of the original bitmap image. When you scale

a bitmap image, you can specify a filter and whether to maintain the aspect ratio of the original image. The filter controls the

interpolation of the scaled bitmap image.

The following table describes the filtering options and illustrates the effects of the filter on a scaled image.

Filter Description

FILTER_BOX This filter has fast performance but provides a bitmap image of low quality.

FILTER_BILINEAR This filter has performance that is slower than the FILTER_BOX filter but provides an image

of better quality.

FILTER_LANCZOS This filter has slow performance but provides a bitmap image of high quality.

For more information about bitmap scaling, see the BlackBerry Java Application Multimedia Development Guide and the API

reference for the BlackBerry® Java® Development Environment.

Bitmap image comparison

You can compare bitmap images by using the Bitmap.locateDifference() method that is provided in the

net.rim.device.api.system package. For example, you can compare two versions of an image changes that were made

to the image. After you identify the changes, you can render only the parts that changed and avoid repainting a screen

unnecessarily.

For more information about comparing bitmap images, see the BlackBerry Java Application Multimedia Development Guide

and the API reference for the BlackBerry® Java® Development Environment.

Feature and Technical Overview

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