KNFB Reader for Windows 10 Quick Start Guide


Welcome to the world of rapid, efficient text recognition and reading with KNFB Reader for Windows 10. This guide will help you learn to use the KNFB Reader app on your Windows 10 mobile device or PC. KNFB Reader will enable you to read most printed documents just seconds after taking a picture.

What KNFB Reader Can Do

KNFB Reader can read a wide variety of document types you may encounter throughout the day. It performs particularly well for reading printed memos, reports, fliers, and virtually any other kind of document typically printed from a personal computer. It will also read many professionally printed items of various sizes, colors, and styles, including:

  • Books
  • Magazines
  • Most restaurant menus
  • Utility bills
  • Printed mailing addresses
  • Class or conference handouts
  • Hotel bills
  • Printed receipts
  • Airline boarding passes
  • Labels on packaged foods showing contents and nutrition information
  • Transit brochures and schedules
  • CD labels

What KNFB Reader Cannot Do

KNFB Reader has been developed to recognize and process a wide variety of type styles, printing formats, and lighting conditions. However, as computer software, the app is not quite as adaptable as the human brain.

You can expect some printed matter to be read accurately with very high reliability, but in other instances performance with a particular type of print or item may not meet your needs. In general you should give KNFB Reader a try with things you need to read. This will help you to learn best what to expect.

KNFB Reader is not designed for use with handwriting or scrolling text on a screen or sign. Accuracy for household product containers (food boxes, tea bags, milk containers, detergent bottles, etc.) may vary, especially if the written information on these containers is artistically presented or is surrounded by pictures and graphics.

Circumstances that may decrease accuracy include:

  • text printed on cylinders with warped or incomplete images (such as soup cans or medicine bottles)
  • LED and LCD screens with refreshing text (such as digital clocks, computer screens, and cell phone screens)
  • vending machine buttons and instructions
  • engraved print (such as serial numbers) on machines
  • very large printed text
  • posted signs, such as signs on transit vehicles and signs in shop windows
  • conventional, analog clocks

Factors Affecting Accuracy

As with human vision, performance of KNFB Reader will vary depending on several factors, including:

  • surface reflection and glare
  • distance between the camera and the target text
  • text size and variation
  • text layout
  • curvature of the target text
  • wrinkles and creases
  • background images and colors
  • ambient lighting
  • shadows
  • obstructions (such as cords, fingers, or neckties) between the camera and the target text

Except for obstructed images, the app can generally adjust to a normal amount of variability with each of these factors. Nonetheless, some attention should be given to minimize the impact of any of these variables when getting ready to take a picture.

Basic Use – Take a Picture, Display and Read Text

When KNFB Reader first starts up, you will be on the “Acquire Image” screen with focus on the “Take Picture” button.

KNFB Reader will detect all cameras and scanners currently connected to your device. If multiple image sources—cameras and/or scanners—are connected to your device, be sure to select the one you want from the Image Source combo box on this screen. This page will be described in detail later in this manual.

For document cameras

Place your document under the camera. Most cameras should be at a height of approximately 10 to 13 inches or 27 to 32 cm. Check your camera periodically to make sure that the lens is clean and unobstructed. Be sure that no portion of a finger or your hand is close enough to the camera to block the view of the document.

To take a picture, navigate to the “Take Picture” button and press the Space or Enter key. You can also take a picture from anywhere on the Acquire Image screen by using the shortcut combination of Ctrl+T.

For scanners

Place your document in the scanner bed. Squaring the edges of the document with the borders of the device will improve page alignment.

To take a picture, navigate to the “Scan Image” button and press the Space or Enter key. You can also scan an image by using the Ctrl+T shortcut key combination from anywhere on the Acquire Image screen.

Reading Text

The image is then processed for text. If any is found, the text is displayed automatically and read aloud as the Reader screen opens. To pause or resume reading, activate the “Play/Pause” button, which is located near the bottom center of the screen or use the shortcut combination of Ctrl+P.

To navigate through the text, Tab or Shift+Tab to the text display area of the screen and use your screen reader’s standard document review commands, or you can also use the navigation controls located at the bottom of the screen.

Save a Document

To save the document, activate the “Save As” button located at the top of the screen just above the displayed text area or press Ctrl+S as a keyboard shortcut. The file name defaults to the current date and time, or you can press Backspace to delete the default, then enter the file name you want, Tab to “OK,” and press enter.  

To return to the Acquire Image screen and take another picture, use the Ctrl+M keyboard shortcut to activate the main menu or press Backspace to go back, or you can select it from the Main Menu in the upper left-hand corner of the screen.

Picture-taking Tips

Sharp pictures are essential for optimal performance. Be sure to adjust your camera to a height which captures all of the text. For best results, place the text you want to read on a flat surface centered under your document camera. Flatten the document as much as possible. Fill the screen with the view of the document you want to capture.

To confirm your camera position or learn the feel of a well aligned picture, use the “Field of View Report” option. You can obtain a Field of View Report by pressing enter on the “Field of View” button on the Acquire Image screen. You can then adjust the position of the page and repeat the process as needed. The goal is to have the camera  close to the document but still far enough away so all four edges of the document are in the field of view.

Practice will help in the beginning. Use a familiar document printed in clear type on an 8.5 by 11 inch (letter format) or 21 by 29.7 cm (A4 format) white sheet of paper for your initial practice sessions. Place the document on a flat surface having a plain dark matte (not shiny) finish. After some practice with positioning and taking pictures, you will begin to know how KNFB Reader responds. You will also be better prepared to analyze and correct conditions you can control when performance does not measure up. A little practice and persistence can greatly improve performance.

Navigation Basics

This guide describes navigation of KNFB Reader on your PC. If your device has a touch screen, all controls will respond via the standard Windows 10 touch screen gestures. The standard mouse and keyboard commands can also be used.

For instance, Tab, Shift+Tab, the arrow keys, and Space or Enter should serve when navigating or activating any controls. Additionally, shortcut keys have been assigned to most functions. A full list of shortcut commands has been provided at the end of this document in Appendix A, while commonly-used commands are noted in relevant sections.

KNFB Reader is designed with the needs of users of screen access software in mind. Most major screen readers will be fully compatible. Currently, Narrator, NVDA, and JAWS for Windows are known to work quite well.  

Windows Phone Compatibility

As a result of an app built using the Universal Windows Platform (UWP) KNFB Reader is fully compatible with phones and other mobile devices running Windows 10. The Narrator screen access solution included in Windows 10 makes non-visual access to KNFB Reader possible.

Please refer to Microsoft documentation for questions about using Narrator on Windows 10 mobile devices. Remember that Narrator will change the touch interface of your device. Here are a few tips to get you started:

Swipe left and right

A short, fast motion with one finger anywhere on the screen to the left or right will move to the previous or next element.

Flick Up and Down

A short fast motion with one finger anywhere on the screen up or down will change the granularity of the navigation element. For example, flicking down would change from “Character” to “Word.” Swiping to the right would then advance to the next word.


Activate the currently selected item by double-tapping anywhere on the screen with one finger.

Additional Tips

  • Touch the screen and slide your finger to navigate spatially.
  • Go back by selecting the “Back” button—typically located in the bottom left corner of the screen.

PDF and Image Files

One of the most common uses of KNFB Reader, especially on a desktop, laptop, or notebook computer is recognition of otherwise inaccessible PDF documents.

PDF, PNG, and JPG files may be imported in to KNFB Reader for text processing using the “Open With” function. This means that if you have an image-based PDF or JPG file that you know contains text, importing the file in to KNFB Reader will enable you to rapidly process the file, extract any text, and have the contents read aloud and available in Braille as provided by your chosen screen access software.

Getting Help

Learning from others is perhaps the best way to master use of KNFB Reader. An email list is maintained by the National Federation of the Blind for this purpose.

To subscribe, go to, or send an email to and put the word “Subscribe” in the subject field.

If you still have questions after you have studied this guide and consulted the user list, please email a request for assistance to

Contact Us:  (347) 422-7085

Appendix A: List of Shortcut Keys


Ctrl + M

Toggle Menu


Previous screen

Alt + C

Acquire Image Screen

Alt + F

File Explorer Screen

Alt + R

Reader Screen

Alt + S

Settings Screen


Stop all speech

Acquire Image

Ctrl + F  

Field of View

Ctrl + B

Activate Batch Mode

Ctrl + T

Take Picture/Scan Document


Ctrl + P  

Toggle Play/Pause


Previous page


Next page

Ctrl + F  

Next sentence

Ctrl + B  

Previous sentence

Ctrl + S  

Save as

Ctrl + R  

Redo OCR

Ctrl + I   

View scanned image

Ctrl + N

Add a new page

File Explorer

Ctrl + E

Explore files on your device

Shift + F10

Open Context file menu

Application key

Open Context file menu

Appendix B: Compatible Cameras and Scanners

Generally, any Windows 10 compatible scanner or camera should work, though some drivers may bring up inaccessible windows. This is beyond the control of KNFB Reader.


  • HoverCam Solo 8
  • HoverCam 5
  • ZiggiCam
  • A selection of unbranded web cams


  • CanoScan LIDE 210
  • Plustek OpticBook 4800

Appendix C: Requirements for Running KNFB Reader


Any device capable of installing and running Windows 10 should be able to accommodate KNFB Reader. Older machines and those with low amounts of available RAM may run more slowly. Decreasing the resolution of images may help, though there is of course a minimum at which text may not be recognized as well. This will vary depending on the particular configuration.

Appendix D: Known Issues

It is recommended that your computer be restarted after connecting a camera or scanner. Not doing so may produce unpredictable results within KNFB Reader.

When Narrator is running, the reading volume of KNFB Reader may be too low to hear. This can be resolved by switching to the Narrator settings screen and pressing the General button, then  uncheck the option “Lower the volume of other apps when Narrator is speaking.”


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