将AWT图像转换为SVG图像 [英] converting AWT image to SVG Image
问题描述
我正在使用以下代码提取AWT图像(从PDF,通过PDFBox):
I am ingesting an AWT image (from PDF, through PDFBox) with the following code:
private java.awt.Graphics2D graphics;
public void drawImage(java.awt.Image awtImage, java.awt.geom.AffineTransform at) {
graphics.setComposite(getGraphicsState().getStrokeJavaComposite());
graphics.setClip(getGraphicsState().getCurrentClippingPath());
graphics.drawImage( awtImage, at, null );
}
,并希望将图像捕获/输出为SVG.我一直在使用Batik库,该库生成以下形式的svg
and wish to capture/output the image as SVG. I have been using the Batik library which produces svg of the form
<image x="0" y="0" transform="matrix(0.144,0,0,0.1439,251.521,271.844)"
clip-path="url(#clipPath2)" width="1797" xlink:href="data:image/png;
base64,iVBORw0KGgoAAAANSUhEUgAABwUAAAV4CAMAAAB2DvLsAAADAFBMVEX////+/v56
enpWVlZbW1taWlpZWVnHx8eRkZFVVVWMjIysrKxXV1dYWFhqamr5+fnMzMxeXl7c
3NyUlJR/f3+3t7cAAACGhob29vYpKSliYmJPT083Nzf8/PyBgYENDQ3s7OwwMDD1
...
RERERERERERERERERERERERERERERERERERERERERERERERERERERERERERERERE
RPQP/R8CiIK+y8Q6KQAAAABJRU5ErkJggg==" height="1400"
preserveAspectRatio="none" stroke-width="0" xmlns:xlink="http://www.w3.org/1999/xlink"/>
我有我自己的SVG库,想将方法添加到SVGImage类中以产生类似的东西.我需要将AffineTransformation应用于数据吗?如果是,怎么办?
I have my own SVG library and want to add methods to my SVGImage class to produce something similar. Do I need to apply the AffineTransformation to the data, and if so how?
非常感谢您指出可以执行此操作的适当(F/OSS)方法或库.数据应该是内联的(如上例所示)且符合XML.
I would be grateful to be pointed to appropriate (F/OSS) methods or libraries that can do this. The data should be inline (as in the above example) and XML-compliant.
更新:在没有任何答案或评论的情况下,我不得不编写自己的实现.这并不完全是琐碎的事情,可能不是可靠的或最佳的解决方案.我将其作为答案-如果有缺陷或可以改进,请发表评论.
UPDATE: In the absence of any answer or comments I have had to write my own implementation. This wasn't completely trivial and may not be robust or the best solution. I append it as an answer - please comment if it's flawed or could be improved.
推荐答案
[回答自己的问题]
[ANSWERING OWN QUESTION]
我认为java.awt.Image
是BufferedImage
,因为它具有适当的方法.在目前的情况下,这已经奏效了(到目前为止).
I assume the java.awt.Image
is a BufferedImage
as that has the appropriate methods. In the present case this has worked (so far).
SVG需要图像的MIME类型(例如"image/png
").
ImageIO
需要一种类型,例如"PNG
".
mimeType2ImageTypeMap
映射这些.
Base64编解码器取自Xerces,但周围有很多.
DOM实现是XOM,属性构造为xlink提供了命名空间
The SVG needs the MIME type of the image (e.g. "image/png
").
ImageIO
needs a type such as "PNG
".
mimeType2ImageTypeMap
maps these.
The Base64 codec is taken from Xerces but there are a lot around.
The DOM implementation is XOM and the attribute construction provides the namespace for xlink
public class SVGImage extends xom.nu.Element {
private static final String DATA = "data";
private static final String BASE64 = "base64";
public static final String IMAGE_PNG = "image/png";
public static final String PNG = "PNG";
private static final String XLINK_PREF = "xlink";
private static final String HREF = "href";
private static final String XLINK_NS = "http://www.w3.org/1999/xlink";
public void readImageData(BufferedImage bufferedImage, String mimeType) {
String type = mimeType2ImageTypeMap.get(mimeType);
if (type == null) {
throw new RuntimeException("Cannot convert mimeType: "+mimeType);
}
double x = bufferedImage.getMinX();
double y = bufferedImage.getMinY();
double height = bufferedImage.getHeight();
double width = bufferedImage.getWidth();
this.setX(x);
this.setY(y);
this.setWidth(width);
this.setHeight(height);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
ImageIO.write(bufferedImage, type, baos);
} catch (IOException e) {
throw new RuntimeException("Cannot read image", e);
}
byte[] byteArray = baos.toByteArray();
String base64 = Base64.encode(byteArray);
String attValue = DATA+":"+mimeType+";"+BASE64+","+base64;
this.addAttribute(new Attribute(XLINK_PREF+":"+HREF, XLINK_NS, attValue));
}
}
上面的代码已在一个测试用例上工作,因此我很乐观地将其扩展到大型图像和其他MIME类型,但尚未对其进行测试.
The code above has worked on a test case so I am optimistic it will scale to large Images and other MIME types but haven't tested them.
是:我必须应用仿射变换.我已经有了一些实用程序,可以将3 * 2的double矩阵转换为SVG transform="matrix(...)"
属性.所以我的最终代码是:
YES: I do have to apply the affine transformation. I already have utility routines for this which convert a 3*2 matrix of doubles to an SVG transform="matrix(...)"
attribute. So my final code is:
Transform2 t2 = new Transform2(at); // converts matrix syntax
BufferedImage bImage = (BufferedImage) awtImage;
SVGImage svgImage = new SVGImage();
svgImage.setTransform(t2);
svgImage.readImageData(bImage, SVGImage.IMAGE_PNG);
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