PDFBox中的缩放图像模糊

Question

然后，我根据页面大小与图像大小计算缩放的维度，返回:java.awt.dimension[width=562,height=792]我使用下面的代码来计算缩放的维度：

public static Dimension getScaledDimension(Dimension imgSize, Dimension boundary) {
  int original_width = imgSize.width;
  int original_height = imgSize.height;
  int bound_width = boundary.width;
  int bound_height = boundary.height;
  int new_width = original_width;
  int new_height = original_height;

  // first check if we need to scale width
  if (original_width > bound_width) {
    //scale width to fit
    new_width = bound_width;
    //scale height to maintain aspect ratio
    new_height = (new_width * original_height) / original_width;
  }

  // then check if we need to scale even with the new height
  if (new_height > bound_height) {
    //scale height to fit instead
    new_height = bound_height;
    //scale width to maintain aspect ratio
    new_width = (new_height * original_width) / original_height;
  }

  return new Dimension(new_width, new_height);
}

为了实际执行图像缩放，我使用image Scalr API：

BufferedImage newImg = Scalr.resize(img, Scalr.Method.ULTRA_QUALITY, Scalr.Mode.FIT_EXACT, 
  scaledWidth, scaledHeight, Scalr.OP_ANTIALIAS);

我的问题是我做错了什么？当缩放到较小的尺寸时，大的图像不应该被模糊。这与PDF页面的分辨率/大小有关吗？

Answer 1

好的，我找到了一种方法，可以在不丢失质量的情况下添加图像。

实际上，为了使图像不模糊，我让PDFBox调整图像的大小，给它所需的大小。如下面的代码：

PDXObjectImage ximage = new PDJpeg(doc, new FileInputStream(new File("/usr/gyo/my_large_image.jpg")), 1.0f);
PDPageContentStream contentStream = new PDPageContentStream(doc, page, true, false);
Dimension scaledDim = getScaledDimension(new Dimension(ximage.getWidth(),  ximage.getHeight()), page.getMediaBox().createDimension());
contentStream.drawXObject(ximage, 1, 1, scaledDim.width, scaledDim.height);
contentStream.close();

谢谢你,