KNFB Reader User Manual

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User Guide for KNFB Reader iOS app

K-NFB Reading Technology, INC.
Copyright © 2014 K-NFB Reading Technology, Inc./ Sensotec nv
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Learning the power of your reader

Welcome to the world of rapid efficient text recognition and reading with our life changing KNFB Reader iPhone app. This Guide will help you learn to use the KNFB Reader app on your iPhone. The KNFB Reader app will enable you to read most printed documents within seconds after taking a picture.

What the KNFB Reader Can Do

The KNFB Reader app, 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 the KNFB Reader Cannot Do

The KNFB Reader iOS app 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 need. In general you should give the KNFB Reader app a try with things you need to read. This will help you to learn best what to expect.

The KNFB Reader app 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.

Other circumstances that may lower 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 the KNFB Reader app 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.

Take a picture, display and read text.

When the KNFBReader app first starts up, you will be in the Image Capture screen. with VoiceOver focus on the Take Picture button. With the screen of the phone facing up, place the iPhone down with the camera in the center of the document with the phone in the same orientation as the document, portrait orientation is recommended, and lift the device straight up approximately eight to ten inches (letter format documents) or 27 to 32 cm (A4 format documents). Held in this position, the camera is on the under side of the phone in the far right hand corner away from you. (Check your camera periodically to make sure that the lens is clean and unobstructed). Be sure to hold the phone so no portion of a finger or your hand is close enough to the camera to block the view of the document. For a normal 8 and one half by 11 inch (letter format) or 21 by 29.7cm (A4 format) sheet, the camera will see the entire page at a distance of 8 to 10 inches or 27 to 32 cm.

To take a picture touch the left side of the screen, and VoiceOver should say: “take picture.” Then you can gently double tap anywhere on the left hand side of the screen and the camera will respond with the distinctive sound of the shutter.

For best results, to avoid jiggling the phone while the picture is taken, try using a split tap command where two fingers are planted firmly on the left hand side of the screen and then lift one finger to snap the picture. Hold the iPhone steady until you hear the camera shutter sound.

The image is processed for text.If any is found, the text is displayed automatically and read aloud as the Text Navigation screen opens. To pause or resume reading, double tap with two fingers together. Use the VoiceOver roater and standard gestures to navigate through the text or additionally by using the navigation controls located at the bottom of the screen.

To save the document, activate the Save Document button located just above the recognized text in the right hand corner of the screen. To return to Image Capture for taking another picture, activate the Back button or perform the VoiceOver scrub gesture to go back.

Picture taking tips.

Sharp pictures are essential for optimal performance. Hold the iPhone steady by using both hands and brace your elbows on the reading surface, while still keeping the device far enough from the document to capture all the text. For best results, place the text you want to read on a flat surface in front of you. Flatten the document as much as possible. Keep the iPhone level over the page.

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 lined up picture, use the Field of View Report option. You can activate the Field of View Report by double tapping or split tapping the right hand side of the screen and holding the phone still to listen to the report; you can then adjust the position of the iPhone above the page and repeat the process as needed. The goal is to have the phone close to the document but still far enough away that all four edges of the document are seen by the camera.

Practice will help in the beginning. Use a familiar document printed in clear type on an 8 and one half 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, not shiny background. After some practice with aiming and taking pictures you will begin to know how the KNFB Reader app 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 will instruct you on navigating the KNFB Reader app on your iDevice using the built in gesture based screenreader called VoiceOver. An overview of how to use VoiceOver in iOS can be located by navigating to the VoiceOver for iOS page on the Apple website

Visit The Apple Web Site To View The Document

. This document assumes that the user has basic knowledge of how to navigate using VoiceOver and does not serve as a replacement for VoiceOver training.

Instructions for navigating the KNFB Reader app may reference the following
basic VoiceOver gestures.
? Flick left/right with one finger: move backward or forward by element
? Flick down/up with one finger: Moves forward or backward using the currently selected element set by the VoiceOver rotor
? Double tap with one finger: activate the control currently in focus
? Split tap using two fingers: placing two fingers on the screen and lifting one performs the action of a double tap
? Flick left/right with three fingers: moves forward or backward through a document by page
? Double tap with two fingers: Pause and Resume speech
? Double tap with four fingers: Toggle VoiceOver help

Image Capture screen

The KNFB Reader app opens to the Image Capture screen but several other screens are also used for reading text and performing other functions in the app. Think of the image capture screen as the home screen for the app. To activate a control or to change a setting, with VoiceOver enabled, double tap with one finger or use a split tap command for best results when taking pictures.

The next few sections will discuss using the controls on the image capture screen in greater detail.

Screen layout

When the KNFB Reader app is launched for the first time, the VoiceOver focus will be on the “Take Picture” button. The controls on this screen going from left to right, and top to bottom inVoiceOver swipe order are as follows.

? File Explorer
? Settings
? Camera Flash
? Take Picture
? Field of View Report
? Tilt Guidance
? Batch Mode
? Text Detection Language
? Document Type
? Select Profile

File Explorer—on Image Capture screen in the upper left hand corner

The “File Explorer” screen is where your saved files are located. Double tap on the “File Explorer” button to access the File Explorer screen.

Activate the back button to return to the previous screen.

Three tabs across the bottom of the file explorer screen separate the different file types available to work with. Files are listed by date with the oldest file appearing first and the newest appearing last in the list. Double tap the edit button to access additional file management

related actions including export options, renaming, and deleting saved documents. Saved documents may also be deleted using a flick up gesture followed by a double tap with the actions item selected in the VoiceOver rotor.

Scanned files

The scanned files tab is where the list of documents that you elect to save during the image capture process will be located. Double tap on a file name to open an read the saved document.

PDF and image files

PDF and jpg files may be imported in to the KNFB Reader app 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 the KNFB Reader app will enable you to rapidly process the file and extract any text and have the contents read aloud and available in Braille.

A sample workflow for extracting text from a pdf or jpg file would function as follows.
? Navigate to a pdf or jpg email attachment
? Using the share option, open the file in the KNFB Reader app
? Double tap on the imported file and activate the scan button to extract text to be read aloud.

Settings button—located on Image Capture screen swiping right from File Explorer

The settings screen consists of three tabs with various controls for changing the way the app functions. Accessing specific settings in any of the tabs may be accomplished by double tapping on the desired tab to select it. To exit settings and return to the image capture screen, activate the back button located on the top left of the screen.

Moving from left to right, the tabs on the settings screen are as follows.
? Visual tab
? General tab
? Info tab

Visual Tab

When the settings screen is activated, the visual tab is automatically selected. The visual tab contains two categories of settings which are indicated by headings, for changing the way text is displayed on screen. The two headings are text settings and highlight settings.

Text settings include
? Text font
? Text size
? Text color
? Background color
? Line distance

Highlight settings include
? Highlight text color
? Highlight background color

General Tab

The general tab contains three toggle settings which are flashlight, automatic reading after OCR and Speak in background. Double tap the switch to toggle the desired function.

The flashlight setting,when enabled, will turn on the LED light located next to the back camera, which you can use as a light source for taking pictures in the dark or in low-light conditions. Please keep in mind that when the flashlight is enabled for long periods of time, the battery may drain faster.

The automatic reading after OCR toggle determines whether or not text will be read immediately after the image is captured and text is available. This setting is enabled by default. Disabling it will cause the KNFB Reader app to seem slower since the page needs to fully process before text can be read with VoiceOver.

The Speak in background toggle determines whether or not speech stops when switching the app to standby.

Info tab

The info tab is where the app version, copyright information, quick start, acknowledgements and user guide may be located.

Camera Flash—on Image Capture screen swiping right from Settings

To take the perfect picture for optimal text results, it is important to have an adequate lighting environment. The camera flash control located on the image capture screen can be cycled between three settings:
automatic, on, and off
with always on set as the default. The automatic flash setting utilizes the light sensor on the camera to determine whether additional lighting is necessary and triggers the LED flash when the reading environment is too dark.

Cycling between flash modes may provide better text results depending on the material of the document being captured. As an example, there may be instances where disabling the flash may provide better text results from a glossy brochure or computer monitor.

Take Picture button—on Image Capture screen swiping right from Camera Flash

The Take Picture button can be found by swiping right from the Camera Flash control or by touching anywhere on the left hand portion of the screen and then using a double tap or split tap command to take the picture.

The KNFB Reader app has been designed to make it simple to capture images quickly and efficiently. As mentioned earlier in this guide, the best images for extracting text have all four edges in the field of view of the camera. The most efficient method for accomplishing this is to lay the iDevice in the center of the document and raise it straight up approximately eight to ten inches (letter format) or 27 to 32 cm (A4 format) before taking the picture. The device can be held in landscape or portrait position relative to the document, but remember that the camera is located in the top right hand corner so avoid covering it with your hand or finger.

Field of view report—on Image Capture screen swiping right from Take Picture

The Field of View Report button can be found by swiping right from the Take Picture control or by touching anywhere on the right hand portion of the screen and then using a double tap or split tap to activate the report.

The field of view report is available to help in learning how best to align the camera with the document you want to read. Use the field of view report button to have the KNFB Reader app capture an image and announce the position of your camera relative to the document.

Similar to capturing an image for text reading, the camera should be centered over the print material approximately eight to ten inches (letter format) or 27 to 32 cm (A4 format) away in order to have all four edges visible in the picture. An optimal field of view report is all four edges are visible, rotated zero degrees clockwise. This means that the entire document is visible in the frame and no text will be cut off. Practicing with the field of view report will help with getting a feel for how the camera sees various document sizes and works in different lighting conditions.

Tilt Guidance—on Image Capture screen swiping right from Field of View Report

The tilt guidance setting is an alignment tool that can be toggled on and off to provide vibration feedback on whether the camera is being held level over a document. When this setting is enabled, the iPhone will vibrate in image capture mode when the device is tiltet to the left or right and to the front or back. The vibration pattern pulsates when the device is not level to a desk or table. Rapid pulsing indicates more tilt right to left or front to back, and slower pulsing indicates less tilt. No pulsing means the device is level over the document.

Batch Mode—on Image Capture screen swiping right from Tilt Guidance

Using batch mode is one means to capture, process, and read multipage documents as a single file. To enable batch mode, double tap the batch mode button to toggle the setting on. Once batch mode has been enabled, use the take picture button to capture each page of the document. When all pages have been captured, activate the batch mode control to process the images for text. Announcements will be made after each image has been successfully processed. The text will be read aloud once the last image has been processed.

Text Detection Language—on Image Capture screen swiping right from Batch Mode

The KNFB Reader ap is able to recognize and read printed materials in several languages including:
? English,
? French,
? German,
? Dutch,
? Italian,
? Spanish,
? Swedish,
? Norwegian,
? Portuguese,
? Danish,
? Finnish.

To select an alternative text recognition language, activate the text detection language control, use the language picker to select the desired language and double tap the done button to return to the image capture screen.

Document Type—on Image Capture screen swiping right from Text Detection Language

The KNFB Reader can recognize two distinct document types. The default type is Multi Column, which recognizes single or multi column page layouts and reads the print in the intended order. Switch the document type to Single Column for documents with information in one column relating to information in the next column beside it, such as invoices, where item and price are meant to be read together. The document type options may be selected or changed by activating the document type control, selecting the desired item in the picker, and double tapping the done button to return to the image capture screen.

Select Profile—on Image Capture screen swiping right from Document Type

The KNFB Reader app provides two modes called profiles for capturing images for text recognition. Use the manual profile to take pictures with the double tap or split tap gestures. Use the automatic profile when you want the KNFB Reader to take pictures automatically when the document you want to read is properly lined up and text is detected in the frame. In automatic picture mode, the iDevice should be centered on the document and lifted to the adequate height. Once text is detected and all four edges are in the frame, the picture will be taken and any available text will be read aloud. To make automatic picture mode more efficient, it may be beneficial to use a stationary document scanning stand for your iDevice.

Reading and Text Navigation Screen

This screen is used to display and read text, highlighting each word as it is spoken. You can also navigate through the text, view or change settings relevant to text, spell words, reprocess the image, or save files. To get to this screen you must take a picture in which text is recognized, or by opening a file in File Explorer.

Screen layout

The Reading and text navigation screen has several controls located above and below the document text. The controls on this screen going from left to right above and below the text inVoiceOver swipe order are as follows.
? Back
? Settings
? Show Picture Associated with the Selected Page
? Add Page to Document
? Recognize this page again
? Save Document
? Choose TTS Language
? Choose TTS Speech Rate
?Navigation and Play/Pause Contro

ls Settings—above text on reading screen swiping right from back

Opening the settings screen displays the same options already discussed in Settings from the Image Capture screen, noting especially the adjustments for text font, text size, text color, background color, and distance between lines.

Highlight adjustments include highlight text color and highlight background color.

Show picture associated with page—above text on reading screen swiping right from settings

Activating this control will display the original captured image.

Add page to document—above text on Reading screen swiping right from show picture associated with page.

Double tap this button if you have a multi-page document and you want all pages to be saved together in a single file. Note that you will be prompted to save the first page of a multi-page document by selecting the file name you want or just accepting the default. Then, after the first page is saved, you will be returned to the image capture screen to take the picture and add the second and successive pages by pressing the add page button on the reading screen each time. In this way you can continue to add pages to create a single document, but to end the process the entire file must be saved again after you have added the final page.

Recognize this page again — above text on Reading screen swiping right from Add Page.

Activate this control to reprocess and read the latest image captured in a different text detection language or in the opposite document type, for example Single Column instead of Multi Column.

Save document—above text on Reading screen swiping right from Recognize this page again.

The text displayed on the Reading screen after you have taken a picture will be disguarded unless you activate the save option before leaving that screen.

Activating the save document button will display a dialog with a text entry field for the file name prefilled with the date and time. Text may be modified in the entry field for a file name you are more likely to recall. Double tap the save button to confirm the process and write the file to memory. Saved files may be accessed by navigating to file explorer on the image capture screen.

Choose TTS language—below text on Reading screen swiping right after last word of text

Activating this control displays a language picker where an alternative language for the reading voice can be selected. Swipe right and then double tap done to close the language picker.

Choose TTS speech rate—below text on Reading screen swiping right from choose TTS language.

This setting controls the speed at which the Reader reads text. The possible values range from 0 percent to 100 percent. Double tapping this control will display an adjustment slider for selecting the desired speech rate value.

Navigation and Play/Pause Controls—below text on Reading screen from left to right at bottom

The TTS—text-to-speech—controls include Previous sentence, previous element, play/pause, next element, and next sentence.

These buttons function similar to Daisy player controls for navigating through the recognized text.

Getting help.

Learning from others is perhaps the best way to master use of the KNFB Reader app. An email list to help you do this is maintained by the National Federation of the Blind. To subscribe, go to
Subscribe To KNFB Reader E Mail List

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: Sensotec nv, Vlamingveld 8, 8490 Jabbeke.

Updated on ... July 28, 2016