Java实现将PPT(.ppt和.pptx)转为图片_Java

本文介绍了使用java将ppt文件转换为图片的方法，支持.ppt和.pptx两种格式。通过apache poi库处理ppt文件内容，利用batik rasterizer生成高质量图片。

核心实现包括：

1）设置字体映射和渲染参数；
2）按幻灯片页数循环转换；
3）自动裁剪图片空白边缘。

代码提供了对两种ppt格式的处理类(ppttoimageutils)和图片处理工具类(imageutils)，建议使用jdk11及以上版本和poi5.2.3版本以确保兼容性。该方法可批量转换ppt为png图片，适用于文档自动化处理场景

1. maven引入

<!-- for .pptx files (office 2007+) -->
<dependency>
    <groupid>org.apache.poi</groupid>
    <artifactid>poi-ooxml</artifactid>
    <version>5.2.3</version>
</dependency>
<!-- for .ppt files (office 97-2003) -->
<dependency>
    <groupid>org.apache.poi</groupid>
    <artifactid>poi-scratchpad</artifactid>
    <version>5.2.3</version>
</dependency>
<dependency>
    <groupid>org.apache.xmlgraphics</groupid>
    <artifactid>batik-rasterizer</artifactid>
    <version>1.14</version>
</dependency>

2. 代码

2.1 ppttoimageutils

import cn.iocoder.yudao.module.agent.util.ppt.imageutils;
import lombok.extern.slf4j.slf4j;
import org.apache.commons.lang3.stringutils;
import org.apache.poi.hslf.usermodel.*;
import org.apache.poi.openxml4j.util.zipsecurefile;
import org.apache.poi.xslf.usermodel.*;
import org.springframework.stereotype.component;

import javax.imageio.imageio;
import java.awt.*;
import java.awt.geom.rectangle2d;
import java.awt.image.bufferedimage;
import java.io.file;
import java.io.fileinputstream;
import java.io.ioexception;
import java.nio.file.files;
import java.nio.file.paths;
import java.util.list;
import java.util.*;
import java.util.stream.collectors;

@slf4j
@component
public class ppttoimageutils {
    private static final map<string, font> font_map = new hashmap<>();
    private static final string default_font = "宋体";

    static {
        graphicsenvironment environment = graphicsenvironment.getlocalgraphicsenvironment();
        for (font font : environment.getallfonts()) {
            addfont(font);
        }
        log.info("supporting fonts: \n{}", stringutils.join(font_map.keyset(), '\n'));
        // 降低压缩比阈值，防止误判正常 emf 文件
        zipsecurefile.setmininflateratio(0.001);
        // 设置最大条目大小（100mb）
        zipsecurefile.setmaxentrysize(100 * 1024 * 1024);
    }

    @suppresswarnings("weakeraccess")
    public static void addfont(font font) {
        font_map.put(font.getfamily(), font);
    }

    /**
     * 将ppt文件转换为多张图像
     *
     * @param pptfile   ppt文件路径
     * @param outputdir 输出目录
     * @return 生成的图像文件路径列表
     */
    public static list<string> convertppttoimages(string pptfile, string outputdir) throws ioexception {
        if (pptfile.endswith("pptx")) {
            return dopptxtoimages(pptfile, outputdir);
        } else if (pptfile.endswith("ppt")) {
            return doppttoimages(pptfile, outputdir);
        } else
            return new arraylist<>();
    }
    
    /**
     * 将ppt文件转换为多张图像
     *
     * @param pptfile   ppt文件路径
     * @param outputdir 输出目录
     * @return 生成的图像文件路径列表
     */
    public static list<string> dopptxtoimages(string pptfile, string outputdir) throws ioexception {
        list<string> imagepaths = new arraylist<>();

        try (fileinputstream is = new fileinputstream(pptfile);
             xmlslideshow ppt = new xmlslideshow(is)) {

            // 创建输出目录
            files.createdirectories(paths.get(outputdir));

            // 获取ppt尺寸
            dimension pagesize = ppt.getpagesize();

            // 计算带边距的尺寸
            int width = (int) pagesize.getwidth();
            int height = (int) pagesize.getheight();
            // 设置缩放比例以提高图像质量
            double scale = 2;
            int scaledwidth = (int) (width * scale);
            int scaledheight = (int) (width * scale);

            list<xslfslide> slides = ppt.getslides();
            log.info(">>>>ppt转图片:{}页开始>>>>", slides.size());
            int index = 1;
            for (int i = 0; i < slides.size(); i++) {
                final int slidenum = index;
                system.out.println("converting slide " + slidenum + "...");
                log.info(">>>>ppt转图片第{}页>>>>", i + 1);
                xslfslide slide = slides.get(i);
                fixfont(slide);
                    // 创建缓冲图像
                log.info(">>>>ppt转图片第{}页,{}>>>>", i + 1, "创建缓冲图像开始");
                bufferedimage img = new bufferedimage(scaledwidth, scaledheight, bufferedimage.type_int_rgb);
                graphics2d graphics = img.creategraphics();

                // 设置渲染提示以提高质量
                log.info(">>>>ppt转图片第{}页,{}>>>>", i + 1, "设置渲染提示以提高质量开始");
                graphics.setrenderinghint(renderinghints.key_antialiasing, renderinghints.value_antialias_on);
                graphics.setrenderinghint(renderinghints.key_rendering, renderinghints.value_render_quality);
                graphics.setrenderinghint(renderinghints.key_interpolation, renderinghints.value_interpolation_bicubic);
                graphics.setrenderinghint(renderinghints.key_fractionalmetrics, renderinghints.value_fractionalmetrics_on);

                // 设置背景为白色
                log.info(">>>>ppt转图片第{}页,{}>>>>", i + 1, "设置背景为白色开始");
//                        color transparentcolor = new color(255, 0, 0, 0);
//                        graphics.setpaint(transparentcolor);
                graphics.setcolor(color.white);
                graphics.setpaint(color.white);
                // 禁用所有透明相关功能
                graphics.setcomposite(alphacomposite.srcover);
                graphics.setbackground(color.white);
                graphics.fill(new rectangle2d.float(0, 0, scaledwidth, scaledheight));

                // 缩放图形上下文
                log.info(">>>>ppt转图片第{}页,{}>>>>", i + 1, "缩放图形上下文开始");
                graphics.scale(scale, scale);

                // 绘制幻灯片
                log.info(">>>>ppt转图片第{}页,{}>>>>", i + 1, "绘制幻灯片开始");
                slide.draw(graphics);

                // 保存图像
                log.info(">>>>ppt转图片第{}页,{}>>>>", i + 1, "保存图像开始");
                string outputpath = string.format("%s/slide_%03d.png", outputdir, i + 1);
                imageio.write(img, "png", new file(outputpath));
                log.info(">>>>ppt转图片第{}页:{}>>>>", i + 1, outputpath);
                imagepaths.add(outputpath);
                graphics.dispose();
                //切掉白色空白区域
                imageutils.imagewhitespace(outputpath);
            }

            index++;
        } catch (exception e) {
            e.printstacktrace();
            log.error(e.getmessage(), e);
        }

        return imagepaths;
    }


    /**
     * 将ppt文件转换为多张图像
     *
     * @param pptfile   ppt文件路径
     * @param outputdir 输出目录
     * @return 生成的图像文件路径列表
     */
    public static list<string> doppttoimages(string pptfile, string outputdir) throws ioexception {
        list<string> imagepaths = new arraylist<>();

        try (fileinputstream is = new fileinputstream(pptfile);
             hslfslideshow ppt = new hslfslideshow(is)) {

            // 创建输出目录
            files.createdirectories(paths.get(outputdir));

            // 获取ppt尺寸
            dimension pagesize = ppt.getpagesize();

            // 计算带边距的尺寸
//            double marginwidth  = pagesize.width   * 20 / 100;
//            double marginheight = pagesize.height * 20 / 100;
            int width = (int) pagesize.getwidth();
            int height = (int) pagesize.getheight();
            // 设置缩放比例以提高图像质量
            double scale = 2.0;
            int scaledwidth = (int) (width * scale);
            int scaledheight = (int) (width * scale);

            list<hslfslide> slides = ppt.getslides();
            for (int i = 0; i < slides.size(); i++) {
                hslfslide slide = slides.get(i);
//                system.out.println("页码: " + (i+1));
                fixhfont(slide);
                // 创建缓冲图像
                bufferedimage img = new bufferedimage(scaledwidth, scaledheight, bufferedimage.type_byte_gray);
                graphics2d graphics = img.creategraphics();

                // 设置渲染提示以提高质量
//                graphics.setrenderinghint(renderinghints.key_antialiasing, renderinghints.value_antialias_on);
//                graphics.setrenderinghint(renderinghints.key_rendering, renderinghints.value_render_quality);
//                graphics.setrenderinghint(renderinghints.key_interpolation, renderinghints.value_interpolation_bicubic);
//                graphics.setrenderinghint(renderinghints.key_fractionalmetrics, renderinghints.value_fractionalmetrics_on);

                // 设置背景为白色
                graphics.setpaint(color.white);
                graphics.fill(new rectangle2d.float(0, 0, scaledwidth, scaledheight));

                // 缩放图形上下文
                graphics.scale(scale, scale);

                // 绘制幻灯片
                slide.draw(graphics);

                // 保存图像
                string outputpath = string.format("%s/slide_%03d.png", outputdir, i + 1);
                imageio.write(img, "png", new file(outputpath));
                imagepaths.add(outputpath);
                graphics.dispose();
                //切掉白色空白区域
                imageutils.imagewhitespace(outputpath);
            }
        } catch (exception e) {
            e.printstacktrace();
        }

        return imagepaths;
    }


    private static void fixfont(xslfslide slide) {
        for (xslfshape shape : slide.getshapes()) {
            if (shape instanceof xslftextshape) {
                for (xslftextparagraph p : ((xslftextshape) shape).gettextparagraphs()) {
                    for (xslftextrun r : p.gettextruns()) {
                        r.setfontfamily(default_font);   // 或“wenquanyi zen hei”
//                        if (r.getfontcolor()==null)
                        r.setfontcolor(color.black);
                    }
                }
            }
        }
    }

    private static void fixhfont(hslfslide slide) {
        for (hslfshape shape : slide.getshapes()) {
            if (shape instanceof hslftextshape) {
                for (hslftextparagraph p : ((hslftextshape) shape).gettextparagraphs()) {
                    for (hslftextrun r : p.gettextruns()) {
                        r.setfontfamily(default_font);   // 或“wenquanyi zen hei”
//                        if (r.getfontcolor()==null)
                        r.setfontcolor(color.black);
                    }
                }
            } else if (shape instanceof hslftable) {
                hslftable shape1 = (hslftable) shape;
                int r = shape1.getnumberofrows();
                int c = shape1.getnumberofcolumns();
                for (int i = 0; i < r; i++) {
                    for (int j = 0; j < c; j++) {
                        hslftablecell cell = shape1.getcell(i, j);
                        for (hslftextparagraph p : cell) {
                            for (hslftextrun text : p.gettextruns()) {
                                text.setfontfamily(default_font);   // 或“wenquanyi zen hei”
//                                if (r.getfontcolor()==null)
                                text.setfontcolor(color.black);
                            }
                        }
                    }
                }
            }
        }
    }


    public static void main(string[] args) throws ioexception {
        string pptfile = "e:/文档/项目.pptx";
        string outputdir = "e:/文档/temp";
        list<string> imagepaths = convertppttoimages(pptfile, outputdir);
    }
}

2.2 imageutils

import javax.imageio.imageio;
import java.awt.image.bufferedimage;
import java.io.file;

public class imageutils {
    public static boolean imagewhitespace(string filepath) {
        try {
            // 读取原始图像
            bufferedimage originalimage = imageio.read(new file(filepath));
            int width = originalimage.getwidth();
            int height = originalimage.getheight();

            // 从底部向上扫描，检测白色区域
            int whitethreshold = 0xffffff - 10; // 接近白色的阈值（允许微小差异）
            int bottomblankheight = 0;
            boolean isblank = true;

            for (int y = height - 1; y >= 0 && isblank; y--) {
                for (int x = 0; x < width; x++) {
                    int pixel = originalimage.getrgb(x, y) & 0xffffff;
                    if (pixel < whitethreshold) {
                        isblank = false;
                        break;
                    }
                }
                if (isblank) {
                    bottomblankheight++;
                }
            }

            // 计算需要裁剪的空白高度（去掉90%）
            int cropheight = (int) (bottomblankheight * 0.9);
            int newheight = height - cropheight ;
            // 裁剪图像（保留上方部分）
            bufferedimage croppedimage = originalimage.getsubimage(0, 0, width, newheight < 1080 ? 1080 : newheight);
            // 保存结果
            imageio.write(croppedimage, "png", new file(filepath));
//            system.out.println("下方空白区域已裁剪约90%，保存为 slide_010_cropped.png");
        } catch (exception e) {
            e.printstacktrace();
            return false;
        }
        return true;
    }

    public static void main(string[] args) {
        string filepath = "e:/文档/temp/slide_005.png";
        imagewhitespace(filepath);
    }
}