Assistive devices - cheap and DIY ideas

04.06.2011 22:03

Digital magnifier for visually impaired from webcam - DIY concept.

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česká verze textu zde

Dear readers of this section,
I'm glad I can introduce concept of new tool, you can make yourself. As you know, commercially available CCTV magnifiers for visually impaired people or for people with residual vision are very expensive and price ranges in the hundreds of dollars. There are two basic types: stand magnifier (you move the magnifier on the text, the magnifier is portable) or a table magnifier (you move the text, magnifier is not portable).
    We want to introduce here a concept of stand magnifier without barriers - i. e. affordably priced and available almost anywhere an for everyone. Please note that this is only a first draft and it will be necessary to improve the construction and maybe also the features of this tool. As the base is necessary to buy a web camera (without autofocus or with autofocus - it is better but more expensive) that you can buy for less then 50 dollars. Consequently, it is necessary to construct such a stand, which will make it possible to move the camera according to your requirements. By increasing or decreasing the vertical distance between the camera and text you achieve the desired magnification of the text. To make text appear on screen just open the webcam viewer (in our case program Cheese within the Linux distribution Vinux was used). Below, if your eyes are OK, you can see both pictures and video showing how the magnifier works.
    APPEAL! I call on all capable programmers who would like to to participate in this project as volunteers. To improve the comfort of working with webcam magnifier, we would need such a software (optimally open-source) program where we can, for example to change the background color or the text, inverse colors, or guide lines for reading materials, etc. Such software is still only a commercial. If you are interested in cooperation, please do not hesitate to contact me. You do a good turn, as this will help many poor eyes:)
Technical note: maybe it would be enough just to modify some existing open-source program (in Linux, there is Cheese for example) by modifying the GUI and adding appropriate color filters etc. I would be better, of course, if the program could be cross-platform, but do not know if it is possible. It would be also very useful if this software could be accessible for Screen readers etc. Open-source license then makes it possible to cooperate with world-wide community and to use components from other open-source programs to save time.

 

Photos:

Webcam used for our concept:

Stand - orange screw on the top for fine camera vertical position tuning, red lever for coarse setting:

 Stand and webcam before mounting:

Stand with mounted camera (no screws or tools needed):

 At work:

Illustration images - related with appeal on programmers - necessary features and color filters of Magnifier/Webcam software:

- following images all come from a real picture take with the described webcam, the color effects etc. were done later in opensource bitmap graphics editor GIMP, with a little help of Inkscape

Source image

The same image, only switched to grayscale:

 

The same image, only switched to grayscale and then to inverse mode:

Image in high-contrast mode black on white (done in GIMP by Colors/Levels) - much better than standard grayscale mode:

 

Image in high-contrast mode white on black (done in GIMP by Colors/Levels) - much better than standard grayscale mode:

 

Image in high-contrast mode - blue on yellow (done in GIMP by Colors/Levels, then replacing the colors - black with blue, white with yellow) - very good contrast, many users prefer this mode instead of black/white high contrast:

 

Image in high-contrast mode - yellow on blue (done in GIMP by Colors/Levels, then replacing the colors - white with blue, black with yellow) - very good contrast, many users prefer this mode instead of black/white high contrast:

 

Image in high-contrast mode black on white (done in GIMP by Colors/Levels) - much better than standard grayscale mode. Displayed guide line (red) for better focusing on the text row:

 

 

2. Light box – light panel

Use: Light box is used for visual stimulation of small children. Usable also for adults.

How to make it: We can use a decommissioned  LCD screen  - could also be a monitor with a defect like cracked display. Then you need to make some basic adjustments - manageable with basic tools and some technical skills:)

First, it is necessary tohave a display with working backlight - never mind any other defects. It is necessary to carefully open the plastic chassis of the monitor so that it can be later screwed together again. Open the monitor and carefully dismantle to have access to the LCD display, which we have to carefully remove (preferably whole).

Remove the screen, but leave all diffuser folies and plastic covers under it at the original location. Be careful because under this plastic cover are located the fluorescent tubes which are very fragile. The lcd display is then replaced with plexiglass or at least a thin plastic sheet.

 

 

Dear visitors, if you are interrested in this area and have some advice, suggestions, questions etc., feel free to email me - my personal email is petrahele(at)gmail(dot)com

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Comments

Datum: 21.11.2011

Vložil: Matthew Brush

Titulek: Digital Magnifier Software

https://github.com/codebrainz/digimag

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Datum: 05.06.2011

Vložil: M

Titulek: Congrats

Well done! Congratulations!!

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