Converting PDF Documents to Image Formats

You can use the Convert PDF service to programmatically convert PDF documents to image formats, which include JPEG, JPEG 2000, TIFF, and PNG. By converting a PDF document to an image file, you can use the PDF document as an image file. For example, you can place the image in an enterprise content management system for storage.

When converting a PDF document to an image, the Convert PDF service creates a separate image for each page in the document. That is, if the document has 20 pages, the Convert PDF service creates 20 image files. When converting a PDF document to an image format, you can create individual images for each page within the PDF document or a single image file for the entire PDF document.

注意: For more information about the Convert PDF service, see Services Reference for LiveCycle.

Summary of steps

To convert a PDF document to any of the supported types, perform the following steps:

  1. Include project files.

  2. Create a Convert PDF service client.

  3. Retrieve the PDF document to convert.

  4. Set run-time options.

  5. Convert the PDF to an image.

  6. Retrieve the image files from a collection.

Include project files

Include the necessary files into your development project. If you are creating a client application by using Java, include the necessary JAR files. If you are using web services, make sure you include the proxy files.

Create a Convert PDF client

Before you can programmatically perform a Convert PDF service operation, you must create a Convert PDF service client. If you are using the Java API, create a ConvertPdfServiceClient object. If you are using the web service API, create a ConvertPDFServiceService object.

Retrieve the PDF document to convert

You must retrieve the PDF document to convert to an image. You cannot convert an interactive PDF document to an image. If you attempt to do so, an exception is thrown. To convert an interactive PDF document to an image file, you must flatten the PDF document before you convert it. (See Flattening PDF Documents.)

Set run-time options

You must set run-time options such as the image format and the resolution values. For information about the run-time values, see the ToImageOptionsSpec class reference in LiveCycle API Reference.

Convert the PDF to an image

After you create the service client and set run-time options, you can convert the PDF document to an image. A collection object that contains the images is returned.

Retrieve the image files from a collection

You can retrieve image files from a collection object that the Convert PDF service returns. Each element in the collection is a com.adobe.idp.Document instance (or a BLOB instance if you are using web services) that you can save as an image file, such as a JPG file.

The format of the image file is dependent on the ImageConvertFormat run-time option. That is, if you set the ImageConvertFormat run-time option to ImageConvertFormat.JPEG, you can save image files as JPG files.

Convert a PDF document to image files using the Java API

Convert a PDF document to an image format by using the Convert PDF service API (Java):

  1. Include project files.

    Include client JAR files, such as adobe-convertpdf-client.jar, in your Java project’s class path.

  2. Create a Convert PDF client.

    • Create a ServiceClientFactory object that contains connection properties.

    • Create a ConvertPdfServiceClient object by using its constructor and passing the ServiceClientFactory object.

  3. Retrieve the PDF document to convert.

    • Create a java.io.FileInputStream object that represents the PDF document to convert by using its constructor and passing a string value that specifies the location of the PDF document.

    • Create a com.adobe.idp.Document object by using its constructor and passing the java.io.FileInputStream object.

  4. Set run-time options.

    • Create a ToImageOptionsSpec object by using its constructor.

    • Invoke methods that belong to this object as required. For example, set the image type by invoking the setImageConvertFormat method and passing an ImageConvertFormat enum value that specifies the format type.

    注意: Setting the ImageConvertFormat enumeration value is mandatory.
  5. Convert the PDF to an image.

    Invoke the ConvertPdfServiceClient object’s toImage2 method and pass the following values:

    • A com.adobe.idp.Document object that represents the PDF file to convert.

    • A com.adobe.livecycle.converpdfservice.client.ToImageOptionsSpec object that contains the various preferences about the target image format.

    The toImage2 method returns a java.util.List object that contains images. Each element in the collection is a com.adobe.idp.Document instance.

  6. Retrieve the image files from a collection.

    Iterate through the java.util.List object to determine whether images are present. Each element is a com.adobe.idp.Document instance. Save the image by invoking the com.adobe.idp.Document object’s copyToFile method and passing a java.io.File object.

Convert a PDF document to image files using the web service API

Convert a PDF document to an image format by using the Convert PDF Service API (web service):

  1. Include project files.

    Create a Microsoft .NET project that uses MTOM. Ensure that you use the following WSDL definition: http://localhost:8080/soap/services/ConvertPDFService?WSDL&lc_version=9.0.1.

    注意: Replace localhost with the IP address of the server hosting LiveCycle.
  2. Create a convert PDF client.

    • Create a ConvertPdfServiceClient object by using its default constructor.

    • Create a ConvertPdfServiceClient.Endpoint.Address object by using the System.ServiceModel.EndpointAddress constructor. Pass a string value that specifies the WSDL to the LiveCycle service (for example, http://localhost:8080/soap/services/ConvertPDFService?blob=mtom.) You do not need to use the lc_version attribute. However, specify ?blob=mtom.

    • Create a System.ServiceModel.BasicHttpBinding object by getting the value of the ConvertPdfServiceClient.Endpoint.Binding field. Cast the return value to BasicHttpBinding.

    • Set the System.ServiceModel.BasicHttpBinding object’s MessageEncoding field to WSMessageEncoding.Mtom. This value ensures that MTOM is used.

    • Enable basic HTTP authentication by performing the following tasks:

      • Assign the LiveCycle user name to the field ConvertPdfServiceClient.ClientCredentials.UserName.UserName.

      • Assign the corresponding password value to the field ConvertPdfServiceClient.ClientCredentials.UserName.Password.

      • Assign the constant value HttpClientCredentialType.Basic to the field BasicHttpBindingSecurity.Transport.ClientCredentialType.

      • Assign the constant value BasicHttpSecurityMode.TransportCredentialOnly to the field BasicHttpBindingSecurity.Security.Mode.

  3. Retrieve the PDF document to convert.

    • Create a BLOB object by using its constructor. This BLOB object is used to store the PDF form.

    • Create a System.IO.FileStream object by invoking its constructor. Pass a string value that specifies the location of the PDF form and the mode to open the file in.

    • Create a byte array that stores the content of the System.IO.FileStream object. Determine the size of the byte array by getting the System.IO.FileStream object’s Length property.

    • Populate the byte array with stream data by invoking the System.IO.FileStream object’s Read method. Pass the byte array, the starting position, and the stream length to read.

    • Populate the BLOB object by assigning its MTOM field with the contents of the byte array.

  4. Set run-time options.

    • Create a ToImageOptionsSpec object by using its constructor.

    • Invoke methods that belong to this object as required. For example, set the image type by invoking the setImageConvertFormat method and passing an ImageConvertFormat enumeration value that specifies the format type.

    注意: Setting the ImageConvertFormat enumeration value is mandatory.
  5. Convert the PDF to an image.

    Invoke the ConvertPDFServiceService object’s toImage2 method and pass the following values:

    • A BLOB object that represents the file to be converted

    • A ToImageOptionsSpec object that contains the various preferences about the target image format

    The toImage2 method returns a MyArrayOfBLOB object that contains the newly created image files.

  6. Retrieve the image files from a collection.

    • Determine the number of elements in the MyArrayOfBLOB object by getting the value of its Count field. Each element is a BLOB object that contains the image.

    • Iterate through the MyArrayOfBLOB object and save each image file.