Scan a paper document to PDF
You can create a PDF file directly from a paper document, using your scanner and Acrobat DC. On Windows, Acrobat DC supports TWAIN scanner drivers and Windows Image Acquisition (WIA) drivers. On Mac OS, Acrobat DC supports TWAIN and Image Capture (ICA).
In Windows, you can either use the Autodetect Color Mode and let Acrobat determine the paper document’s content type, or use other presets (Black & White Document, Grayscale Document, Color Image, and Color Document) based on your judgment. You can configure the scanning presets or use the Custom Scan option to scan with the settings of your choice.
Preset scanning is available only for scanner drivers that support Hide Scanner’s Native Interface mode. The scanning presets are not available on Mac OS.
In Windows, if a WIA driver is installed for your scanner, you can use the Scan button on your scanner to create a PDF. Press the Scan button, and then in Windows, choose Adobe Acrobat DC from the list of registered applications. Then, in the Acrobat DC Scan dialog box, select a scanner and a document preset or Custom Scan.
If you specify that you want to use the native scanner user interface instead of the Acrobat user interface, other windows or dialog boxes appear. Consult the scanner documentation information on available options. In Mac OS, the scanner user interface is always shown.
Select options in the Secondary toolbar - click the Settings icon and choose appropriate options in the Enhance Scanned PDF dialog box, and click OK.
For more information on the options displayed in the dialog box, see Enhance Scanned PDF dialog box.
Select an installed scanner. You must have the manufacturer scanning software installed on your computer. In Windows only, click the Options button to specify scanner options.
Specify single or double-sided scanning. If you select Both Sides and the settings of the scanner are for only one side, the scanner setting overrides the Acrobat settings.
You can scan both sides of pages even on scanners that do not themselves support two-sided scanning. When Both Sides is selected, a dialog box appears after the first sides are scanned. You can then reverse the original paper documents in the tray, and select the Scan Reverse Side (Put Reverse Of Sheets) option in that dialog box. This method produces a PDF with all pages in the proper sequence.
Color Mode (Windows only)
Select a basic color mode (Autodetect, Color, Black and White, or Grayscale) that your scanner supports. This option is enabled if your Scanner Options are set to use the Acrobat scanning dialog box instead of the scanner application.
Resolution (Windows only)
Select a resolution that your scanner supports. This option is enabled if your Scanner Options are set to use the Acrobat scanning dialog box instead of the scanner application.
If you select a Color Mode or Resolution option not supported by your scanner, a message appears and your scanner application window opens. Select different options in the scanner application window.
Prompt For Scanning More Pages
When selected, a dialog box prompting you to scan additional pages appears after every scanning session.
Creates multiple files from multiple paper documents. Click More Options, and specify whether to create a PDF Portfolio of the files, the number of pages for each file, and a filename prefix. These options are not available in the Configure Presets dialog box.
Append To Existing File Or Portfolio
Adds the converted scan to an existing PDF or PDF Portfolio. This option is not available in the Configure Presets dialog box.
Optimize Scanned Pages
Select this option to run the optimization process on the PDF. This option is used to compresses and filter the images in the scanned PDF.
Small Size/High Quality
Drag the slider to set the balance point between file size and quality. Click Options to customize optimization with specific settings for file compression and filtering.
Make Searchable (Run OCR)
Select this option to convert text images in the PDF to searchable and selectable text. This option applies optical character recognition (OCR) and font and page recognition to the text images. Click Options to specify settings in the Recognize Text - Settings dialog box. See Recognize text in scanned documents.
Make PDF/A Compliant
Select this option to make the PDF conform to ISO standards for PDF/A-1b. When selected, only Searchable Image is available in the Recognize Text - Settings dialog box for the PDF Output Style option.
When selected, the Document Properties dialog box appears after scanning. In the Document Properties dialog box, you can add metadata, or information about the scanned document, to the PDF file. If you are creating multiple files, you can enter common metadata for all of the files.
Data Transfer Method
Native Mode transfers in the default mode for your scanner. Memory Mode is automatically selected for scanning in resolutions over 600 dots per inch (dpi).
The Hide Scanner’s Native Interface option bypasses the windows and dialog boxes provided by the scanner manufacturer. Instead, scanning starts directly with the settings specified in the Custom Scan settings.
Invert Black And White Images
This option creates positive images from black-and-white negatives, for example.
The Enhance Scanned PDF dialog box controls the image settings of how scanned images are filtered and compressed for the PDF. Default settings are suitable for a wide range of document pages, but you may want to customize settings for higher-quality images, smaller file sizes, or scanning issues.
Apply Adaptive Compression
Divides each page into black-and-white, grayscale, and color regions and chooses a representation that preserves appearance while highly compressing each type of content. The recommended scanning resolutions are 300 dots per inch (dpi) for grayscale and RGB input, or 600 dpi for black-and-white input.
The scanner uses either the selected Color/Grayscale option or the selected Monochrome option. Which one is used depends on the settings you select in the Acrobat Scan dialog box or in the scanner’s TWAIN interface, which may open after you click Scan in the Acrobat Scan dialog box. (By default, the scanner application dialog box does not open.)
JBIG2 (Lossless) & JBIG2(Lossy)
Applies the JBIG2 compression method to black-and-white input pages. Highest-quality levels use the lossless method; at lower settings, text is highly compressed. Text pages typically are 60% smaller than CCITT Group 4 compressed pages, but processing is slow. Compatible with Acrobat 5.0 (PDF 1.4) and later.
For compatibility with Acrobat 4.0, use a compression method other than JBIG2.
Rotates any page that is not square with the sides of the scanner bed, to make the PDF page align vertically. Choose On or Off.
Whitens nearly white areas of grayscale and color input (not black-and-white input).
For best results, calibrate your scanner’s contrast and brightness settings so that a scan of a normal black-and-white page has dark gray or black text and a white background. Then, Off or Low should produce good results. If scanning off-white paper or newsprint, use Medium or High to clean up the page.
Removes halftone dot structure, which can reduce JPEG compression, cause moire patterns, and make text difficult to recognize. Suitable for 200–400-dpi grayscale or RGB input or, for Adaptive Compression, 400–600-dpi black-and-white input. The On setting (recommended) applies the filter for 300 dpi or higher grayscale and RGB input. Select Off when scanning a page with no pictures or filled areas, or when scanning at a resolution higher than the effective range.
Sharpens the text of the scanned PDF file. The default value of low is suitable for most documents. Increase it if the quality of the printed document is low and the text is unclear.
By default the OCR language is picked from default locale. To change the language, click Edit and choose a different language.
Acrobat scanning accepts images between 10 dpi and 3000 dpi. If you select Searchable Image or ClearScan for PDF Output Style, input resolution of 72 dpi or higher is required. Also, input resolution higher than 600 dpi is downsampled to 600 dpi or lower.
To apply lossless compression to a scanned image, select one of these options under the Optimization Options in the Optimize Scanned PDF dialog box: CCITT Group 4 for monochrome images, or Lossless for color or grayscale images. If this image is appended to a PDF document, and you save the file using the Save option, the scanned image remains uncompressed. If you save the PDF using Save As, the scanned image may be compressed.
For most pages, black-and-white scanning at 300 dpi produces text best suited for conversion. At 150 dpi, OCR accuracy is slightly lower, and more font-recognition errors occur; at 400 dpi and higher resolution, processing slows, and compressed pages are bigger. If a page has many unrecognized words or small text (9 points or smaller), try scanning at higher resolution. Scan in black and white whenever possible.
When Recognize Text Using OCR is disabled, full 10-to-3000 dpi resolution range may be used, but the recommended resolution is 72 and higher dpi. For Adaptive Compression, 300 dpi is recommended for grayscale or RGB input, or 600 dpi for black-and-white input.
Pages scanned in 24-bit color, 300 dpi, at 8-1/2–by-11 in. (21.59-by-27.94 cm) result in large images (25 MB) before compression. Your system may require 50 MB of virtual memory or more to scan the image. At 600 dpi, both scanning and processing typically are about four times slower than at 300 dpi.
Avoid dithering or halftone scanner settings. These settings can improve the appearance of photographs, but they make it difficult to recognize text.
For text printed on colored paper, try increasing the brightness and contrast by about 10%. If your scanner has color-filtering capability, consider using a filter or lamp that drops out the background color. Or if the text isn’t crisp or drops out, try adjusting scanner contrast and brightness to clarify the scan.
If your scanner has a manual brightness control, adjust it so that characters are clean and well formed. If characters are touching, use a higher (brighter) setting. If characters are separated, use a lower (darker) setting.
Recognize text in scanned documents
You can use Acrobat DC to recognize text in previously scanned documents that have already been converted to PDF. Optical character recognition (OCR) software enables you to search, correct, and copy the text in a scanned PDF. To apply OCR to a PDF, the original scanner resolution must have been set at 72 dpi or higher.
Scanning at 300 dpi produces the best text for conversion. At 150 dpi, OCR accuracy is slightly lower.
Output (PDF Output Style)
Determines the type of PDF to produce. All options require an input resolution of 72 dpi or higher (recommended). All formats apply OCR and font and page recognition to the text images and convert them to normal text.
Decreases the number of pixels in color, grayscale, and monochrome images after OCR is complete. Choose the degree of downsampling to apply. Higher-numbered options do less downsampling, producing higher-resolution PDFs.
Correct OCR text in PDFs
When you run OCR on a scanned output, Acrobat DC analyzes bitmaps of text and substitutes words and characters for those bitmap areas. If the ideal substitution is uncertain, Acrobat DC marks the word as suspect. Suspects appear in the PDF as the original bitmap of the word, but the text is included on an invisible layer behind the bitmap of the word. This method makes the word searchable even though it is displayed as a bitmap.
Note: If you try to select text in a scanned PDF that does not have OCR applied, or try to perform a Read Out Loud operation on an image file, Acrobat DC asks if you want to run OCR. If you click OK, the Text Recognition dialog box opens and you can select options, which are described in detail under the previous topic.