Transcript The Path to Accessible PDFs - Web Accessibility at Johns
The Path to Accessible PDFs
Sandra Clark Senior Developer The Constella Group [email protected]
Overview
• Why PDF’s • Definitions • Creating a New PDF with Microsoft Word • Converting an existing PDF to an Accessible Format • Checking Accessibility • Increasing Accessibility 2
Why PDF’s
• Different Platforms = Same Look • Content Control Retention – Documents cannot easily be altered – Printing and content extraction can be limited • Print and Online, looks the same 3
Definitions
• • • Image Only PDF – – – Scanned image, no actual text Not Accessible Requires OCR before it can be made accessible.
Searchable PDF – – – Text Content Not Tagged Not Accessible Tagged PDF – Contains a Document structure – Searchable and Accessible 4
Tagged PDF
• Tags provide structure and hierarchy to a document • This structure can control the reading order • Tags improve – Accessibility – Forms – Language Definition 5
Adobe Versions and Accessibility
• • • • With each version Adobe has implemented greater ease in implementing accessibility Adobe 5 – First version to produce Tagged PDFs – Accessibility provided by a plugin Adobe 6 – First version to natively implement accessibility Adobe 7 – Added Touch Up Tool and other devices to aid in creating accessible PDFs.
– Acrobat 7 Professional supports form development 6
Creating a New PDF - Programs
• Accessible PDFs can be created most effectively with Microsoft Office 2000 and above. • Adobe’s Desktop Publishing Software, Pagemaker and InDesign will also work well in creating Accessible PDFs 7
Creating a New PDF – Microsoft Word
• • Acrobat installs plugins into Office Products To ensure a properly tagged document is created, the conversion settings of the PDF Maker must be set up.
– The default settings should produce a tagged PDF document • Conversion Settings Check – With the document open in MS Word • Choose Adobe PDF from the menu bar and select “Change Conversion Settings • Make sure “Enable accessibility and reflow with Tagged PDF” is checked 8
Create your document
• Just as with HTML, your Word document should be properly structured with styles.
– Follow a proper information hierarchy.
• Don’t use tabs or spaces to visually present information.
– Format the styles in MS Word to visually present your information.
• If you are going to create columns, use the columns creator under the format menu to do so, don’t use tabs.
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Save your document
• Choose Adobe PDF from the menu bar – Select “Convert to Adobe PDF” • Name and save the file • Open Adobe Acrobat to continue working with the tagged document.
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PDF’s with Images
• If images are used within a document created in the above manner, remember that all images must have alternative text that describes the image.
– If a lengthy text description is required, consider inserting it into the document itself either preceding or following the image.
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To create alternative text in MS Word
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2.
Select the image and perform a right-click operation Select “Format Picture” 3.
Under the Web Tag a.
Enter a short description of the image.
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i.
Be descriptive as to what the image is and (if necessary) its purpose Click “OK” 12
Converting an existing PDF
• In order to create an accessible PDF, Acrobat needs to separate the content from the presentation.
• With items that are not created using the process described earlier, that conversion needs to be done within Acrobat.
– Depending on the structure (or lack thereof) of the document, this can be a slow and tedious process.
– Whenever possible, if a document was not created in an accessible manner, find the original and work it within MS Word and create the structure there prior to working with it as a PDF.
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Converting Existing PDF Recommendations
• • • If an original document exists – – Open the document in an MS Office application.
Format the document using the style elements as described earlier and add appropriate image descriptors.
If the original document does not exist – Open the PDF document in Acrobat and work with it in there as described in the following slides If the original PDF is an “image only” document – Use an OCR program to transfer it to text – – Bring it into an MS Office Application Reformat the document using the style elements.
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Adding Tags to a PDF Document - Benefits
• Adding Tags to a PDF document ensures greater user accessibility – It also allows for saving of PDF document to alternative formats such as HTML – Provides the ability to “reflow” text information to fit different screen dimensions 15
Adding Tags to a PDF Document Limitations
• When Acrobat adds tags to a PDF Document there are no guarantees that the reading order will be correct.
• High complexity documents may not be tagged in a way that follows the logical reading order of the original – Visually Rich Layouts – Complex Data Tables • Graphics and Charts may not be processed correctly and may be rendered as “Figures” – These items will need to be identified and have the appropriate alternative text descriptions added.
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How to add Tags to a document
• Open the PDF document that does not contain tags.
• Select “Advanced/Accessibility” from the menu • Choose “Add Tags to Document” • Choose “Save As” and save the file with a new name after the processing • Open the new PDF file and review the results.
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Touch Up Reading Order Tool
• • New for Acrobat 7 Allows the editor to evaluate the PDF reading order and make the necessary corrections • Identifies the blocks of text, headings, figures, tables, etc that are contained in the document structure.
– Identifying text can be added to an image using this tool.
• Don’t use the Reading Order Tag to manually add all the tags for your document. – Use the Add Tags to Document function first and then reorganize the reading order flow with this tool as necessary.
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The Touch Up Reading Tool
• Use the Touch Up Reading Order Tool to add, edit or remove content and reading order.
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Adding Content
• Some content in the PDF may have been missed when adding tags. So the entire document must be gone through and missing information must be added to the tag structure.
– Text content that is not part of the page structure will not be within a grayed box.
• To add content – When the touchup panel is open your cursor will show up as cross hairs. Use the cross hairs to draw a box around all the text information you want to work with. – Make sure all the text information is surrounded by blue squares.
– Select the type of content from the reading order panel.
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Removing Content
• Sometimes it is necessary to remove content from the document structure. – – Items such as visual images that aren’t relevant to the content – Information that is misrecognized by the tags • When the touch up panel is open – Draw a box, using the cross hairs to surround the information you want to remove.
Select the “Background’ button from the panel.
• This removes the gray regions from the content and removes the content from the document structure 21
Reclassifying Content
• Some information in a page may be classified incorrectly – A Heading might be classified as text 22
To reclassify content in an entire region
• Click on the number in the upper left corner of the region you want to reclassify.
• Select the correct content type from the touch up panel • The selected region is now changed to the requested content type.
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To reclassify content in part of a region
• Draw a box around the content you want to change the classification using the cross hairs.
• Select the correct content type from the touch up panel.
• The regions will now split into two or more distinct regions 24
Controlling Reading Order
• Once tags are added, the reading order must be confirmed.
– Reading order can vary depending on the layout complexity of the document.
• To verify the reading order you must first – Save the file as a “Text (Accessible) type.
– Open the text file and review it for the logical flow.
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Controlling Reading order using the Touch up panel
• • • • Identify the two regions which are not in the correct reading order.
Move the cross hairs cursor to the number in the upper left corner of the region to be moved – The cursor will change to a “hand” Click and drag the number to the new location – Can be within another region.
– You need to place the region precisely.
• The cursor will change to a caret to assist • You may need to increase the zoon level to ensure the correct placement.
Acrobat will automatically renumber to show the order the information will be read in. However, the regions will not move visually in the document itself.
– You are changing the reading order of the document structure, not the visual content.
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The Tags Tab
• The Tags tab allows the user to view the content structure and make changes.
– Acrobat 5 and 6 only have the tags tab – In Acrobat 7, its recommended to use the touch up panel instead.
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Controlling Reading Order with the Tags Tab
• Open the Tags Tab – Open a tagged document in Acrobat – Select “View/Tags” from the menu. • To work with the Tags Tab – Select the appropriate item in the tags tab you want to change and click the right mouse button.
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Tables and PDFs
• • • PDF’s can handle tables that are created as tables in MS Word, provided the table is not very complex.
Tags in markup are similar to those in HTML –