4. Smartphone-based light checking system

Currently, many visually impaired individuals become to use smartphones as well as sighted people, and therefore it is useful to build assistive systems based on smartphones. In this section, we propose a notification system of the ON/OFF states of room lights and elevator button lights by use of a smartphone camera [73].

change of the light by analyzing the intensity histogram and the exchangeable image file format (EXIF) information of an image obtained by the camera. If the light becomes brighter and then darker, the smartphone system will tell the user that the room light turns ON and OFF, respectively. If the user fails to set the smartphone camera, the system returns nothing.

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In a lecture room shown in Figure 19, a user used the proposed system and was able to

(a) (b)

Figure 19. Recognition result of the state of room lights in a lecture room. (a) ON; (b) OFF.

Figure 18. A visually impaired user tries to confirm the ON/OFF state of a room light.

Therefore, the user can be aware of the failure and do again after resetting the camera.

correctly determine that the room lights were turned off.

#### 4.1. Room light

It is said that many visually impaired individuals often use room lights for the prevention of crime, and so on. They cannot confirm (or have difficulties in confirming) the ON/OFF states by seeing the lights, but can change the states by using the switches of the lights.

There are two types of room light switch. Ones are switches that change their shapes according to the ON/OFF states. The others are switches that do not change their shapes. Figures 16 and 17 show examples of the former and latter switches, respectively.

Visually impaired individuals can confirm the ON/OFF states if the switches are the former types, but cannot if the latter. It is necessary to help visually impaired individuals know whether room lights are ON or OFF. This section proposes a notification system of the ON/OFF states of room lights based on interaction between a visually impaired user, a smartphone, a room light, and its switch.

First, a visually impaired user turns a smartphone camera toward a room light and then changes the switch of the light as shown in Figure 18. The system determines the luminosity

Figure 16. Seesaw-type switch. (a) ON; (b) OFF.

Figure 17. Push-type switch. (a) ON; (b) OFF.

change of the light by analyzing the intensity histogram and the exchangeable image file format (EXIF) information of an image obtained by the camera. If the light becomes brighter and then darker, the smartphone system will tell the user that the room light turns ON and OFF, respectively. If the user fails to set the smartphone camera, the system returns nothing. Therefore, the user can be aware of the failure and do again after resetting the camera.

4. Smartphone-based light checking system

122 Causes and Coping with Visual Impairment and Blindness

button lights by use of a smartphone camera [73].

4.1. Room light

and its switch.

Figure 17. Push-type switch. (a) ON; (b) OFF.

Figure 16. Seesaw-type switch. (a) ON; (b) OFF.

Currently, many visually impaired individuals become to use smartphones as well as sighted people, and therefore it is useful to build assistive systems based on smartphones. In this section, we propose a notification system of the ON/OFF states of room lights and elevator

It is said that many visually impaired individuals often use room lights for the prevention of crime, and so on. They cannot confirm (or have difficulties in confirming) the ON/OFF states

There are two types of room light switch. Ones are switches that change their shapes according to the ON/OFF states. The others are switches that do not change their shapes. Figures 16 and

Visually impaired individuals can confirm the ON/OFF states if the switches are the former types, but cannot if the latter. It is necessary to help visually impaired individuals know whether room lights are ON or OFF. This section proposes a notification system of the ON/OFF states of room lights based on interaction between a visually impaired user, a smartphone, a room light,

First, a visually impaired user turns a smartphone camera toward a room light and then changes the switch of the light as shown in Figure 18. The system determines the luminosity

(a) (b)

(a) (b)

by seeing the lights, but can change the states by using the switches of the lights.

17 show examples of the former and latter switches, respectively.

In a lecture room shown in Figure 19, a user used the proposed system and was able to correctly determine that the room lights were turned off.

Figure 18. A visually impaired user tries to confirm the ON/OFF state of a room light.

Figure 19. Recognition result of the state of room lights in a lecture room. (a) ON; (b) OFF.

#### 4.2. Elevator button light

The notification system can be also used to confirm the arrival floor of an elevator cage. The light of a floor button on a control panel in an elevator cage often turns off when the cage arrives at the corresponding floor. By using the system, a visually impaired user can know whether the cage arrives at a desired floor as described below.

5. Conclusion

Acknowledgements

on design of this study.

Author details

Hotaka Takizawa1

References

In this chapter, we proposed three assistive systems for visually impaired individuals based on image processing. The Kinect cane system can detect obstacles of various sizes and also recognize objects such as floors, walls, seats, upward staircases, downward staircases, and elevators. The detection and recognition results are notified to a visually impaired user by means of vibration feedback. The Kinect goggle system is another type of wearable system and can make user's hands free. The system can also detect obstacles and recognize objects. The smartphone-based light checking system can inform a visually impaired user about the ON/ OFF states of room lights and elevator button lights. The user can confirm light states and arrival floors. The experimental results demonstrate that the proposed systems are effective in

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The authors wish to acknowledge Dr. Nobuo Ezaki, Professor of National Institute of Technology, Toba College and Dr. Shinji Mizuno, Professor of Aichi Institute of Technology, for advice

[1] WHO. World health organization, media centre, visual impairment and blindness, fact sheet no. 282. 2014. Available from: http://www.who.int/mediacentre/factsheets/fs282/en/

[2] Dakopoulos D, Bourbakis NG. Wearable obstacle avoidance electronic travel aids for blind: A survey. IEEE Transactions on Systems, Man, and Cybernetics, Part C: Applica-

[3] Benjamin JM, Ali NA, Schepis AF. A laser cane for the blind. In: . Proceedings of the San

This work was supported in part by the JSPS KAKENHI Grant Number 16K01536.

helping visually impaired individuals in everyday environments.

\* and Mayumi Aoyagi<sup>2</sup>

\*Address all correspondence to: takizawa@cs.tsukuba.ac.jp

1 University of Tsukuba, Tsukuba, Japan

2 Aichi University of Education, Kariya, Japan

[Online; Accessed: August 1, 2014]

tions and Reviews. Jan 2010;40(1):25-35

Diego Biomedical Symposium. Vol. 12; 1973. p. 53-57

First, a visually impaired user sets a smartphone camera toward the button of a desired floor as shown in Figure 20 and executes the light notification program. When the cage arrives at the floor, the light of the button will be turned off, and the system tells the user that the light is turned off. By hearing the message, the user can know the current floor.

In Figure 21, a user can correctly determine that he arrived at the ninth floor.

Figure 20. A visually impaired user tries to confirm the current floor.

Figure 21. Recognition result of the state of an elevator button light. (a) ON; (b) OFF.
