从演示文稿形状中提取图像

图像通常被添加到形状中，并且经常用作幻灯片的背景。这些图像对象是通过 IImageCollection 添加的，这是一个 IPPImage 对象的集合。

本文解释了如何提取添加到演示文稿中的图像。

要从演示文稿中提取图像，您必须首先通过遍历每个幻灯片并再遍历每个形状来定位图像。一旦找到或识别图像，您可以提取它并将其保存为新文件。

void Run()
{
    System::String path = u"D:\\Aspose Data\\";
    //访问演示文稿
    System::SharedPtr<Presentation> pres = System::MakeObject<Presentation>(path + u"ExtractImages.pptx");
    System::SharedPtr<Aspose::Slides::IPPImage> img;
    System::SharedPtr<Aspose::Slides::IPPImage> Backimg;

    int32_t slideIndex = 0;
    System::String ImageType = u"";
    bool ifImageFound = false;
    for (int32_t i = 0; i < pres->get_Slides()->get_Count(); i++)
    {
        slideIndex++;
        //访问第一个幻灯片
        System::SharedPtr<ISlide> sl = pres->get_Slides()->idx_get(i);
        System::SharedPtr<System::Drawing::Imaging::ImageFormat> Format = System::Drawing::Imaging::ImageFormat::get_Jpeg();

        if (sl->get_Background()->get_FillFormat()->get_FillType() == Aspose::Slides::FillType::Picture)
        {
            //获取背景图像  
            Backimg = sl->get_Background()->get_FillFormat()->get_PictureFillFormat()->get_Picture()->get_Image();

            //设置所需的图像格式
            ImageType = Backimg->get_ContentType();
            ImageType = ImageType.Remove(0, ImageType.IndexOf(u"/") + 1);
            Format = GetImageFormat(ImageType);

            System::String ImagePath = path + u"BackImage_";
            Backimg->get_SystemImage()->Save(ImagePath + u"Slide_" + System::Convert::ToString(slideIndex) + u"." + ImageType, Format);
        }
        else
        {
            if (sl->get_LayoutSlide()->get_Background()->get_FillFormat()->get_FillType() == Aspose::Slides::FillType::Picture)
            {
                //获取背景图像  
                Backimg = sl->get_LayoutSlide()->get_Background()->get_FillFormat()->get_PictureFillFormat()->get_Picture()->get_Image();

                //设置所需的图像格式 
                ImageType = Backimg->get_ContentType();
                ImageType = ImageType.Remove(0, ImageType.IndexOf(u"/") + 1);
                Format = GetImageFormat(ImageType);

                System::String ImagePath = path + u"BackImage_Slide_" + i;
                Backimg->get_SystemImage()->Save(ImagePath + u"LayoutSlide_" + System::Convert::ToString(slideIndex) + u"." + ImageType, Format);
            }
        }

        for (int32_t j = 0; j < sl->get_Shapes()->get_Count(); j++)
        {
            // 访问包含图像的形状
            System::SharedPtr<IShape> sh = sl->get_Shapes()->idx_get(j);

            if (System::ObjectExt::Is<AutoShape>(sh))
            {
                System::SharedPtr<AutoShape> ashp = System::ExplicitCast<Aspose::Slides::AutoShape>(sh);
                if (ashp->get_FillFormat()->get_FillType() == Aspose::Slides::FillType::Picture)
                {
                    img = ashp->get_FillFormat()->get_PictureFillFormat()->get_Picture()->get_Image();
                    ImageType = img->get_ContentType();
                    ImageType = ImageType.Remove(0, ImageType.IndexOf(u"/") + 1);
                    ifImageFound = true;

                }
            }
            else if (System::ObjectExt::Is<PictureFrame>(sh))
            {
                System::SharedPtr<IPictureFrame> pf = System::ExplicitCast<Aspose::Slides::IPictureFrame>(sh);
                if (pf->get_FillFormat()->get_FillType() == Aspose::Slides::FillType::Picture)
                {
                    img = pf->get_PictureFormat()->get_Picture()->get_Image();
                    ImageType = img->get_ContentType();
                    ImageType = ImageType.Remove(0, ImageType.IndexOf(u"/") + 1);
                    ifImageFound = true;
                }
            }

            //设置首选图像格式
            if (ifImageFound)
            {
                Format = GetImageFormat(ImageType);
                System::String ImagePath = path + u"Slides\\Image_";
                img->get_SystemImage()->Save(ImagePath + u"Slide_" + System::Convert::ToString(slideIndex) + u"_Shape_" + System::Convert::ToString(j) + u"." + ImageType, Format);
            }

            ifImageFound = false;
        }
    }
}

System::SharedPtr<System::Drawing::Imaging::ImageFormat> GetImageFormat(System::String ImageType)
{
    System::SharedPtr<System::Drawing::Imaging::ImageFormat> Format = System::Drawing::Imaging::ImageFormat::get_Jpeg();
    {
        const System::String& switch_value_0 = ImageType;
        do {
            if (switch_value_0 == u"jpeg")
            {
                Format = System::Drawing::Imaging::ImageFormat::get_Jpeg();
                break;
            }
            if (switch_value_0 == u"emf")
            {
                Format = System::Drawing::Imaging::ImageFormat::get_Emf();
                break;
            }
            if (switch_value_0 == u"bmp")
            {
                Format = System::Drawing::Imaging::ImageFormat::get_Bmp();
                break;
            }
            if (switch_value_0 == u"png")
            {
                Format = System::Drawing::Imaging::ImageFormat::get_Png();
                break;
            }
            if (switch_value_0 == u"wmf")
            {
                Format = System::Drawing::Imaging::ImageFormat::get_Wmf();
                break;
            }
            if (switch_value_0 == u"gif")
            {
                Format = System::Drawing::Imaging::ImageFormat::get_Gif();
                break;
            }
        } while (false);
    }

    return Format;
}