Working with Images in PostScript | C++

Add Image in PS Document

Aspose.Page for C++ library offers two methods for adding images to PS document:

• for opaque images;
• for transparent images;

It was made because PostScript doesn’t support transparency, but translucent images, however, can be rendered as a set of fully transparent and fully opaque pixels. Such images are called masks. If we want to see the translucent image in the PS document as mask, that will better reflect the transparency of the image, we should do some checking and preprocessing of such an image.

The check and the preprocessing require time. Therefore, if someone’s sure that the image is fully opaque, it is better to use the first method, because it saves execution time.

The second method recognizes whether the image is fully opaque or fully transparent or translucent. If it is fully opaque it is added as the opaque image in the first method, if it is fully transparent it is not added to the document at all, if it is the translucent image it is added as a PostScript image mask.

In the example below we demonstrate how to add a fully opaque image. Adding a transparent image will be demonstrated in the “Working with Transparency” article.

In order to add an image to a new PsDocument with Aspose.Page for C++ library in this example we take the following steps:

1. Create an output stream for the resulting PS file.
2. Create PsSaveOptions object with default options.
3. Create a 1-paged PsDocument with an already created output stream and save options.
4. Create a new graphics state.
5. Create System.Drawing.Bitmap from image file.
6. Create the necessary transformation for the image.
7. Add the image to the PsDocument object.
8. Exit from the current graphics state to upper level one.
9. Close the page.
10. Save the document.

    // The path to the documents directory.
    System::String dataDir = RunExamples::GetDataDir_WorkingWithImages();
    
    //Create output stream for PostScript document
    {
        System::SharedPtr<System::IO::Stream> outPsStream = System::MakeObject<System::IO::FileStream>(dataDir + u"AddImage_outPS.ps", System::IO::FileMode::Create);
        // Clearing resources under 'using' statement
        System::Details::DisposeGuard<1> __dispose_guard_1({ outPsStream});
        // ------------------------------------------
        
        try
        {
            //Create save options with A4 size
            System::SharedPtr<PsSaveOptions> options = System::MakeObject<PsSaveOptions>();
            
            // Create new 1-paged PS Document
            System::SharedPtr<PsDocument> document = System::MakeObject<PsDocument>(outPsStream, options, false);
            
            
            document->WriteGraphicsSave();
            document->Translate(100.0f, 100.0f);
            
            //Create a Bitmap object from image file
            {
                System::SharedPtr<System::Drawing::Bitmap> image = System::MakeObject<System::Drawing::Bitmap>(dataDir + u"TestImage Format24bppRgb.jpg");
                // Clearing resources under 'using' statement
                System::Details::DisposeGuard<1> __dispose_guard_0({ image});
                // ------------------------------------------
                
                try
                {
                    //Create image transform
                    System::SharedPtr<System::Drawing::Drawing2D::Matrix> transform = System::MakeObject<System::Drawing::Drawing2D::Matrix>();
                    transform->Translate(35.0f, 300.0f);
                    transform->Scale(3.0f, 3.0f);
                    transform->Rotate(-45.0f);
                    
                    //Add image to document
                    document->DrawImage(image, transform, System::Drawing::Color::Empty);
                }
                catch(...)
                {
                    __dispose_guard_0.SetCurrentException(std::current_exception());
                }
            }
            
            document->WriteGraphicsRestore();
            
            //Close current page
            document->ClosePage();
            
            //Save the document
            document->Save();
        }
        catch(...)
        {
            __dispose_guard_1.SetCurrentException(std::current_exception());
        }
    }

See working with images in PS documents in .NET or Java.

The result of running this code is appeared as

You can download examples and data files from GitHub.