我需要使用Java JAI缩放图像。目前,我正在使用以下代码:
private static RenderedOp scale(RenderedOp image, float scale) {
ParameterBlock scaleParams = new ParameterBlock();
scaleParams.addSource(image);
scaleParams.add(scale).add(scale).add(0.0f).add(0.0f);
scaleParams.add(Interpolation.getInstance(Interpolation.INTERP_BICUBIC_2));
// Quality related hints when scaling the image
RenderingHints scalingHints = new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
scalingHints.put(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);
scalingHints.put(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
scalingHints.put(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
scalingHints.put(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
scalingHints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
scalingHints.put(JAI.KEY_BORDER_EXTENDER, BorderExtender.createInstance(BorderExtender.BORDER_COPY));
return JAI.create("scale", scaleParams, scalingHints);
}
很不幸,这导致非常糟糕的结果,特别是因为我经常需要使用小于0.5的比例因子缩放图像... 有什么建议吗?
AffineTransformOp
的理由?请参见 http://stackoverflow.com/questions/4216635 - trashgod