Scan a paper document to PDF and use Acrobat to turn it into a smart, searchable PDF with selectable text.

You can create a PDF file directly from a paper document, using your scanner and Acrobat. On Windows, Acrobat supports TWAIN scanner drivers and Windows Image Acquisition (WIA) drivers. On Mac OS, Acrobat 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.

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 from the list of registered applications. Then, in the Acrobat scan interface, select a scanner and a document preset or Custom Scan.

To scan a paper document to PDF using Acrobat, go to Tools > Create PDF. The Create a PDF from any format interface is displayed. Choose Scanner to see the options available.

On Windows:

On Mac:

After you select a scanner, you can choose or adjust its various scanning options as per your requirements.

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.

• 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.
• Lossless compressions can only be applied to monochrome images. 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 or JBIG2 (Lossless) for monochrome 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 a 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 the 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.

For troubleshooting tips, see Troubleshoot scanner issues when scanning using Acrobat.

You can use Acrobat 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.

When you run OCR on a scanned output, Acrobat analyzes bitmaps of text and substitutes words and characters for those bitmap areas. If the ideal substitution is uncertain, Acrobat 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 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.