java RenderedImage 到 BufferedImage 用于多页 tiff 读取
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RenderedImage to BufferedImage for multipage-tiff reading
提问by Robert
I am using JAI to load in multipage TIFF images
我正在使用 JAI 加载多页 TIFF 图像
File file = workArea[0];
SeekableStream s = new FileSeekableStream(file);
TIFFDecodeParam param = null;
ImageDecoder dec = ImageCodec.createImageDecoder("tiff", s, param);
//first page
RenderedImage op1 =
new NullOpImage(dec.decodeAsRenderedImage(0),
null,
OpImage.OP_IO_BOUND,
null);
BufferedImage pg1 = new BufferedImage(op1.getWidth(), op1.getHeight(),
BufferedImage.TYPE_INT_RGB);
pg1.getGraphics().drawImage((Image) op1, 0, 0, null);
However, in the last line I get a runtime error of:
但是，在最后一行中，我收到了一个运行时错误：
Exception in thread "main" java.lang.ClassCastException:
javax.media.jai.MullOpImage cannot be cast to java.awt.Image
I clear the RenderedImage after attempting to set the BufferedImage so I don't exactly "need" the RenderedImage if there is another method of doing this.
我在尝试设置 BufferedImage 后清除了 RenderedImage，因此如果有另一种方法可以做到这一点，我并不完全“需要”RenderedImage。
I attempted:
我尝试：
pg1.setData(op1.getData());
and that gives an ArrayIndexOutOfBoundsException. I'm not sure why exactly as pg1's width and height are set by op1's, but there is probably a very valid reason.
这给出了一个 ArrayIndexOutOfBoundsException。我不确定为什么 pg1 的宽度和高度完全由 op1 设置，但可能有一个非常有效的理由。
采纳答案by Jeffrey
Use op1.getAsBufferedImage()to create pg1.
使用op1。getAsBufferedImage()创建 pg1。
回答by Robert
I found a solution at http://www.jguru.com/faq/view.jsp?EID=114602
我在http://www.jguru.com/faq/view.jsp?EID=114602找到了解决方案
The first one didn't work, however, the convertRenderedImage function did work.
第一个不起作用，但是， convertRenderedImage 函数起作用了。
public BufferedImage convertRenderedImage(RenderedImage img) {
if (img instanceof BufferedImage) {
return (BufferedImage)img;
}
ColorModel cm = img.getColorModel();
int width = img.getWidth();
int height = img.getHeight();
WritableRaster raster = cm.createCompatibleWritableRaster(width, height);
boolean isAlphaPremultiplied = cm.isAlphaPremultiplied();
Hashtable properties = new Hashtable();
String[] keys = img.getPropertyNames();
if (keys!=null) {
for (int i = 0; i < keys.length; i++) {
properties.put(keys[i], img.getProperty(keys[i]));
}
}
BufferedImage result = new BufferedImage(cm, raster, isAlphaPremultiplied, properties);
img.copyData(raster);
return result;
}
回答by heisbrandon
回答by rogerdpack
JAI apparently has a "converter" class in there:
JAI 显然在那里有一个“转换器”类：
ImageDecoder dec = ImageCodec.createImageDecoder("PNM", new File(input), null);
return new RenderedImageAdapter(dec.decodeAsRenderedImage()).getAsBufferedImage()
ref: http://www.programcreek.com/java-api-examples/index.php?api=com.sun.media.jai.codec.ImageDecoder
参考：http: //www.programcreek.com/java-api-examples/index.php?api= com.sun.media.jai.codec.ImageDecoder
回答by Ankursonikajen
Try this :
试试这个 ：
RenderedImage im = dec.decodeAsRenderedImage();
BufferedImage bi = PlanarImage.wrapRenderedImage(im).getAsBufferedImage();
