Provides extra options to use when saving a document using the Adobe Portable Document Format (PDF).
The options set in the PdfDocumentOptions class will be used when the user saves a document using the DocumentFormat.Pdf format.
The PdfDocumentOptions class contains the following member features:
Member | Description |
---|---|
PdfDocumentOptions.DocumentType | Sets the document type to either PDF or PDF/A. |
PdfDocumentOptions.FontEmbedMode | Controls how fonts are embedded in the resulting PDF document. |
Note that PdfDocumentOptions.FontEmbedMode is not used when | |
saving PDF/A files. All fonts are always embedded in PDF/A files. | |
PdfDocumentOptions.ImageOverText | Adds the original raster image as an overlay on top of the PDF |
content. The resulting document will look exactly like the original | |
document. Use the ImageOverTextSize and ImageOverTextMode | |
properties to control the quality of this image. | |
PdfDocumentOptions.Linearized | A linearized PDF file is a file that has been organized in such |
a way as to enable efficient incremental access in a network | |
environment. This allows the first page of the PDF file to be | |
displayed in a user Web browser before the entire file is | |
downloaded from the Web server. | |
PdfDocumentOptions.Linearized enables the creation of linearized | |
PDF documents. Both PDF and PDF/A formats are supported. | |
PDF Document Metadata | The resulting PDF can contain optional metadata associated with |
the document. This metadata can be used by external search and | |
indexing engines to search and classify PDF documents. | |
Set the document metadata elements with PdfDocumentOptions.Title, | |
PdfDocumentOptions.Subject, PdfDocumentOptions.Author, and | |
PdfDocumentOptions.Keywords. |
Control the initial view properties of the generated PDF file with the following properties.
Property | Description |
---|---|
PageModeType | Page mode, such as page only, page with bookmarks, page with thumbnails, etc. |
PageLayoutType | Page layout, such single page, one column, two pages, etc. |
PageFitType | Page fit, such as none, fit width, height, etc. |
InitialPageNumber | Initial page number to go to. |
XCoordinate and YCoordinate | Position on the page to go to initially. |
ZoomPercent | Zoom percentage to use when the document is opened. |
HideToolbar, HideMenubar, and HideWindowUI | Show or hide various user interface elements. |
FitWindow and CenterWindow | Specify how the document is viewed in the window. |
DisplayDocTitle | Display the document title in the viewer. |
PDF documents can be protected (secured) using two methods:
Protected against viewing. PDF viewers will request a password from the user when the document is opened for viewing. This password is called the user password. The created PDF document can be protected by setting the PdfDocumentOptions.IsProtected property to true and the PdfDocumentOptions.UserPassword property to the password value.
Protected against editing. PDF editors will request a password from the user when the document is opened for editing. This password is called the owner password. The created PDF document can be protected by setting the PdfDocumentOptions.IsProtected property to true and the PdfDocumentOptions.OwnerPassword property to the password value.
When a PDF document is protected against editing (through the use of an owner password), an encryption level and owner access rights can be granted or denied in the resulting document. The following table lists the PDF access rights supported by the LEADTOOLS Document Writers:
Encryption | Owner Access Rights |
---|---|
Low (PdfDocumentOptions.EncryptionMode set to PdfDocumentEncryptionMode.RC40Bit) |
Printing (PdfDocumentOptions.PrintEnabled) Copying text (PdfDocumentOptions.CopyEnabled) Editing (PdfDocumentOptions.EditEnabled) Annotations and comments (PdfDocumentOptions.AnnotationsEnabled) |
High (PdfDocumentOptions.EncryptionMode set to PdfDocumentEncryptionMode.RC128Bit) |
Adds the following to owner access rights supported by low level encryption: High quality printing (PdfDocumentOptions.HighQualityPrintEnabled) Adding/Removing pages (PdfDocumentOptions.AssemblyEnabled) |
The following table shows the suggested PDF document options to use to achieve the smallest output PDF file size while maintaining an acceptable quality.
Property | Value | Remarks |
---|---|---|
OneBitImageCompression | OneBitImageCompressionType.Jbig2 | The JBIG2 format offers the best 1-bit image compression. |
ColoredImageCompression | ColoredImageCompressionType.FlateJpx | JPX offers the best colored image compression (8 or 24 bits per pixel). |
Reverts to flate compression if the image has a bits per pixel value | ||
other than 8 or 24. | ||
ImageOverTextSize | DocumentImageOverTextSize.Half | Only used when using the image over text option (ImageOverText is |
true). The overlay image is sized by half and stretched over the | ||
page. This will save up to 75% of the size while maintaining the | ||
image quality. | ||
ImageOverTextMode | DocumentImageOverTextMode.Relaxed | Only used when using the image over text option (ImageOverText is |
true). Any grayscale overlay image is converted to black and white | ||
while ignoring noise and shadows. | ||
QualityFactor | 50 or 100 | Use 50 when using the image over text option (ImageOverText is |
true). Use 100 when image over text is not used (ImageOverText | ||
is false). | ||
PdfDocumentOptions.FontEmbedMode | DocumentFontEmbedMode.None | Do not embed the fonts in the PDF file. Warning: The resulting PDF is |
not guaranteed to have the same fonts used to create it. Use this option | ||
only if font substituting is acceptable in your particular scenario. | ||
Otherwise, leave this to the default value of DocumentFontEmbedMode.Auto. |
The following code snippet shows how to set the PDF options to produce minimum file size with acceptable quality:
function createPDFOptions(useImageOverText) {
// Create options
var pdfOptions = new lt.Documents.Writers.PdfDocumentOptions();
// Use JBIG2 for B/W images
pdfOptions.oneBitImageCompression = lt.Documents.Writers.OneBitImageCompressionType.jbig2;;
// Use JPEG2000 or Flate for colored images
pdfOptions.coloredImageCompression = lt.Documents.Writers.ColoredImageCompressionType.flateJpx;
// Embed fonts automatically
pdfOptions.fontEmbedMode = lt.Documents.Writers.DocumentFontEmbedMode.auto;
if (useImageOverText) {
// Use image over text
pdfOptions.imageOverText = true;
// Re-size the overlay image by 2
pdfOptions.imageOverTextSize = lt.Documents.Writers.DocumentImageOverTextSize.half;
// Convert grayscale to black and white if possible
pdfOptions.imageOverTextMode = lt.Documents.Writers.DocumentImageOverTextMode.relaxed;
// Use quality factor of 50
pdfOptions.qualityFactor = 50;
} else {
// Will not use image over text
pdfOptions.imageOverText = false;
// Use quality factor of 100
pdfOptions.qualityFactor = 100;
}
// Use this
return pdfOptions;
}
This example will create a new encrypted Adobe Portable Document Format document (PDF) file using the various supported options.
Start with the example from LEADDocument and replace all the code inside the example function (search for the "// TODO: add example code here" comment) with the following code:
import { DocumentHelper } from "../../utilities/DocumentHelper";
export class PdfDocumentOptionsExample {
private el: HTMLElement;
public constructor() {
lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/v200/LEADTOOLSEVAL.txt", "EVAL", null);
DocumentHelper.initFactory();
}
public run = (buttonID: string) => {
this.el = document.getElementById(buttonID);
this.el.onclick = this.loadDocument;
}
loadDocument = () => {
const url = "https://demo.leadtools.com/images/pdf/leadtools.pdf";
DocumentHelper.log("Loading document...");
lt.Document.DocumentFactory.loadFromUri(url, null)
.done((doc: lt.Document.LEADDocument) => {
DocumentHelper.log("Loaded, converting...");
// Create a new PDF document with: PDF and no image/text
const pdfOptions = new lt.Document.Writer.PdfDocumentOptions();
pdfOptions.documentType = lt.Document.Writer.PdfDocumentType.pdf;
pdfOptions.fontEmbedMode = lt.Document.Writer.DocumentFontEmbedMode.none;
pdfOptions.imageOverText = false;
pdfOptions.linearized = false;
pdfOptions.title = "TEST TITLE";
pdfOptions.subject = "TEST SUBJECT";
pdfOptions.keywords = "TEST KEYWORDS";
pdfOptions.author = "TEST AUTHOR";
pdfOptions.isProtected = true;
pdfOptions.userPassword = "password";
pdfOptions.ownerPassword = "Owner password";
pdfOptions.encryptionMode = lt.Document.Writer.PdfDocumentEncryptionMode.rc128Bit;
pdfOptions.printEnabled = false;
pdfOptions.highQualityPrintEnabled = true;
pdfOptions.copyEnabled = false;
pdfOptions.editEnabled = true;
pdfOptions.annotationsEnabled = true;
pdfOptions.assemblyEnabled = false;
pdfOptions.oneBitImageCompression = lt.Document.Writer.OneBitImageCompressionType.flate;
pdfOptions.coloredImageCompression = lt.Document.Writer.ColoredImageCompressionType.flateJpeg;
pdfOptions.qualityFactor = 2;
const jobData = new lt.Document.DocumentConverterJobData();
jobData.documentFormat = lt.Document.Writer.DocumentFormat.pdf;
jobData.rasterImageFormat = lt.Document.RasterImageFormat.unknown;
// Set document options
jobData.documentOptions = pdfOptions;
doc.convert(jobData)
.done((result: any) => {
// This is generic code, we know the result is in "document" since PDF supports that
// But this code checks if the results have been archived into a ZIP file if this
// example was converting to, say SVG
const resultDocument = result.document != null ? result.document.url : result.archive.url;
const link = document.createElement("a");
const url = lt.Document.DocumentFactory.serviceUri + "/" + resultDocument;
link.href = url;
link.innerHTML = url;
link.target = "_default";
DocumentHelper.log("Converted: " + url, url);
this.el.parentElement.insertBefore(link, this.el.parentElement.firstChild);
})
.fail(DocumentHelper.showServiceError);
})
.fail(DocumentHelper.showServiceError);
}
}