使用图像

Aspose.Words允许用户以非常灵活的方式处理图像。 在本文中,您只能探索使用图像的一些可能性。

如何从文档 {#how-to-extract-images-from-a-document}中提取图像

所有图像都存储在文档中的Shape节点中。 要从文档中提取具有特定类型的所有图像或图像,请执行以下步骤:

  • 使用getChildNodes方法选择所有形状节点。
  • 迭代生成的节点集合。
  • 检查hasImage布尔属性。
  • 使用ImageData属性提取图像数据。
  • 将图像数据保存到文件中。
// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
// The path to the documents directory.
String dataDir = Utils.getDataDir(ExtractImagesToFiles.class);
Document doc = new Document(dataDir + "Image.SampleImages.doc");
NodeCollection<Shape> shapes = (NodeCollection<Shape>) doc.getChildNodes(NodeType.SHAPE, true);
int imageIndex = 0;
for (Shape shape : shapes
) {
if (shape.hasImage()) {
String imageFileName = String.format(
"Image.ExportImages.{0}_out_{1}", imageIndex, FileFormatUtil.imageTypeToExtension(shape.getImageData().getImageType()));
shape.getImageData().save(dataDir + imageFileName);
imageIndex++;
}
}

如何在每个文档页面上插入条形码

此示例允许您在Word文档的所有或特定页面上添加相同或不同的条形码。 没有直接的方法可以在文档的所有页面上添加条形码,但您可以使用moveToSectionmoveToHeaderFooter和[insertImage](https://reference.aspose.com/words/java/com.aspose.words/DocumentBuilder#insertImage(byte[]))方法移动到任何部分或页眉/页脚并插入条形码图像,如下面的代码所示。

下面的代码示例演示如何在文档的每页上插入条形码图像:

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
// The path to the documents directory.
String dataDir = Utils.getDataDir(InsertBarcodeImage.class);
Document doc = new Document(dataDir + "Image.SampleImages.doc");
DocumentBuilder builder = new DocumentBuilder(doc);
// The number of pages the document should have.
int numPages = 4;
// The document starts with one section, insert the barcode into this existing section.
InsertBarcodeIntoFooter(builder, doc.getFirstSection(), 1, HeaderFooterType.FOOTER_PRIMARY);
InsertBarcodeIntoFooter(builder, doc.getFirstSection(), 1, HeaderFooterType.FOOTER_PRIMARY);
for (int i = 1; i < numPages; i++) {
// Clone the first section and add it into the end of the document.
Section cloneSection = (Section) doc.getFirstSection().deepClone(false);
// cloneSection.getPageSetup().getSectionStart() = SectionStart.NEW_PAGE;
doc.appendChild(cloneSection);
// Insert the barcode and other information into the footer of the section.
InsertBarcodeIntoFooter(builder, cloneSection, i, HeaderFooterType.FOOTER_PRIMARY);
}
dataDir = dataDir + "Document_out_.docx";
// Save the document as a PDF to disk. You can also save this directly to a stream.
doc.save(dataDir);
// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
private static void InsertBarcodeIntoFooter(DocumentBuilder builder, Section section, int pageId, int footerType) {
// Move to the footer type in the specific section.
try {
builder.moveToSection(section.getDocument().indexOf(section));
builder.moveToHeaderFooter(footerType);
String dataDir = Utils.getDataDir(InsertBarcodeImage.class);
// Insert the barcode, then move to the next line and insert the ID along with the page number.
// Use pageId if you need to insert a different barcode on each page. 0 = First page, 1 = Second page etc.
builder.insertImage(dataDir + "Barcode1.png");
builder.writeln();
builder.write("1234567890");
builder.insertField("PAGE");
// Create a right aligned tab at the right margin.
double tabPos = section.getPageSetup().getPageWidth() - section.getPageSetup().getRightMargin() - section.getPageSetup().getLeftMargin();
builder.getCurrentParagraph().getParagraphFormat().getTabStops().add(new TabStop(tabPos, TabAlignment.RIGHT, TabLeader.NONE));
// Move to the right hand side of the page and insert the page and page total.
builder.write(ControlChar.TAB);
builder.insertField("PAGE");
builder.write(" of ");
builder.insertField("NUMPAGES");
} catch (Exception x) {
}
}

锁定图像 {#lock-aspect-ratio-of-image}的宽高比

几何形状的长宽比是其尺寸在不同尺寸中的比例。 您可以使用AspectRatioLocked锁定图像的宽高比。 形状长宽比的默认值取决于ShapeType。 对于ShapeType.Image为true,对于其他形状类型为false。

下面的代码示例演示如何使用宽高比:

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
// The path to the documents directory.
String dataDir = Utils.getDataDir(DocumentBuilderSetImageAspectRatioLocked.class);
// Open the document.
Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);
Shape shape = builder.insertImage(dataDir + "Test.png");
shape.setAspectRatioLocked(false);
doc.save(dataDir + "output.doc");

如何在点 {#how-to-get-actual-bounds-of-shape-in-points}中获得形状的实际边界

如果您希望在页面上呈现形状的实际边界框,则可以使用BoundsInPoints属性来实现此目的。

下面的代码示例演示如何使用此属性:

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);
Shape shape = builder.insertImage(dataDir + "Test.png");
shape.setAspectRatioLocked(false);
System.out.print("\nGets the actual bounds of the shape in points. ");
System.out.println(shape.getShapeRenderer().getBoundsInPoints());

裁剪图像

图像的裁剪通常是指去除图像的不需要的外部部分,以帮助改善帧。 它还用于去除图像的某些部分,以增加对特定区域的焦点。

下面的代码示例演示如何使用Aspose.WordsAPI实现此目的:

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
// The path to the documents directory.
String dataDir = Utils.getDataDir(CropImages.class);
String inputPath = dataDir + "ch63_Fig0013.jpg";
String outputPath = dataDir + "cropped-1.jpg";
cropImage(inputPath, outputPath, 124, 90, 570, 571);
// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
public static void cropImage(String inPath, String outPath, int left, int top, int width, int height) throws Exception {
Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);
BufferedImage img = ImageIO.read(new File(inPath));
int effectiveWidth = img.getWidth() - width;
int effectiveHeight = img.getHeight() - height;
Shape croppedImage = builder.insertImage(img,
ConvertUtil.pixelToPoint(img.getWidth() - effectiveWidth),
ConvertUtil.pixelToPoint(img.getHeight() - effectiveHeight));
double widthRatio = croppedImage.getWidth() / ConvertUtil.pixelToPoint(img.getWidth());
double heightRatio = croppedImage.getHeight() / ConvertUtil.pixelToPoint(img.getHeight());
if (widthRatio < 1)
croppedImage.getImageData().setCropRight(1 - widthRatio);
if (heightRatio < 1)
croppedImage.getImageData().setCropBottom(1 - heightRatio);
float leftToWidth = (float) left / img.getWidth();
float topToHeight = (float) top / img.getHeight();
croppedImage.getImageData().setCropLeft(leftToWidth);
croppedImage.getImageData().setCropRight(croppedImage.getImageData().getCropRight() - leftToWidth);
croppedImage.getImageData().setCropTop(topToHeight);
croppedImage.getImageData().setCropBottom(croppedImage.getImageData().getCropBottom() - topToHeight);
croppedImage.getShapeRenderer().save(outPath, new ImageSaveOptions(SaveFormat.JPEG));
}

将图像保存为WMF

Aspose.Words提供将文档中所有可用图像保存到 WMF将DOCX转换为RTF时进行格式化。

下面的代码示例演示如何使用RTF保存选项将图像保存为WMF:

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
String fileName = "TestFile.doc";
Document doc = new Document(dataDir + fileName);
RtfSaveOptions saveOpts = new RtfSaveOptions();
saveOpts.setSaveImagesAsWmf(true);
doc.save(dataDir + "output.rtf", saveOpts);