<p>A computer is <em>blind</em> conceptually speaking. Even if you gave it a camera, it cannot "see" per se. It has a translation of what is viewed to bits.</p>

<p>Now to the blind student. Image Processing is similar to how folks without sight process things - they "feel" their environment for "signals" and make a conclusion about what it is.</p>

<p>A computer does the exact same thing, but with math. Ask them to feel a stick. Easy. Now draw the stick on the floor/paper and ask them to say if a stick or triangle exists on the paper. Really hard. Ask them how would <em>they</em> know <em>if</em> a triangle is on the paper. Feel the edges? Anything else? How about everytime there's a triangle a new sound is heard? Be creative.</p>

<p>Now talk to them about "rasterization". Think of handling them one sliver at a time, and if anything is different by feeling, they note it. Can they "conclude" a triangle after seeing various cuts of the paper?</p>

<p>This exercise can be naturally extended to Image Processing and then math can be explained.</p>

<p>Computer Graphics is different. It lives in the visual plane and the idea is to "draw" it. A good introduction is this:</p>

<p><em>Problem statement: Draw a line on a graph/matrix and each "cell" must be filled in. Which cells to fill in between points A and B when "drawing this line".</em></p>

<p>Extending this to blind students could be done with toys/pins etc., How would they know which spots to "fill in" to get as straight a line as possible? What does a "straight line mean"?</p>

<p>This discussion could lead to things about using a line's slope (i.e., math) to figure which pixels to color on a raster display. Same thing with Circles.</p>

<p>I'd start here first. Once that's done, to move to transformations - moving things in space. Easy to feel and then take to the math.</p>

<p>I haven't worked with the blind, but I imagine such exercises/parallels with their sensory world could be useful.</p>

CC BY-SA 3.0
2018-03-16T12:31:48.920Z
This seems not dissimilar from braille, actually.
Ben I.
CC BY-SA 3.0
2018-03-16T20:10:52.073Z
Conceptually. However, what you want the student to grasp is the connection between sight and math as similar to brain and braille. It’s not that much different. You want the student to *think* how to get it done and what one needs to know/learn for that to happen. Appealing to that knowledge center fosters learning a lot better IMHO.
PhD
CC BY-SA 3.0
2018-03-15T20:09:03.273Z
2018-03-15T20:09:03.273Z
PhD
<p>I think you can teach 2D graphics using a tactile approach on a phone or tablet. </p>

<p>Students are very likely to be used to tracing their fingers over a mobile device (I have watched awesome videos of blind iPhone users in action).</p>

<p>So position and shape change of an object could be detected by them dragging their fingers over to get auditory feedback at the edges. Ideally you want a truly tactile surface but I don't know of any such devices. I have my own reasons for wanting a computer-controlled version of <a href="https://rads.stackoverflow.com/amzn/click/B004N7HEYG" rel="nofollow noreferrer">one of these</a> <a href="https://i.sstatic.net/kduJ9.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/kduJ9.jpg" alt="nail picture toy"></a></p>

<p>For actual image processing maybe map colours to tone, so as they move their finger over an image they hear a tone vary depending on the average pixels underneath. Then, as transforms are applied, the tones would change. You could possibly teach colour theory by varying the mapping to only one channel of RGB.</p>

<p><strong>Update</strong> in one of those great examples of synchronicity, a few days after writing the above I was listening to <a href="https://www.swiftbysundell.com/podcast/12" rel="nofollow noreferrer">Matthias Tretter of MindNode on a podcast</a> mention how he had been convinced to add accessibility to MindNode, a <em>visual mindmapping product</em> by a blind user. </p>

<p>His <a href="https://mindnode.com/news/2016-06-29-making-mindnode-accessible" rel="nofollow noreferrer">blog posting</a> has videos showing VoiceOver in action. This is a bit tangential to the original answer but a nice anecdote about how preconceptions about the intended purpose of a tool as being visual doesn't rule it out for blind users.</p>

CC BY-SA 3.0
2018-01-24T12:32:30.517Z
This is a very interesting idea. Thanks for taking the time to answer, and welcome to [cseducators.se]!
thesecretmaster
CC BY-SA 3.0
2018-01-29T14:14:10.287Z
This gave me some ideas: The solitaire game with the jumping marbles, but as a grid https://cdn.pixabay.com/photo/2016/03/31/18/35/solitaire-1294487_960_720.jpg Tactile touch screen (may be not available yet) https://i.ytimg.com/vi/JelhR2iPuw0/maxresdefault.jpg
ctrl-alt-delor
CC BY-SA 3.0
2018-01-24T11:31:53.807Z
2018-01-30T13:14:31.510Z
2018-01-30T13:14:31.510Z
Andy Dent
<h1>Just some ideas</h1>
<p>I imagine that the biggest problem, may be motivation.</p>
<p>It can be all done abstractly: in maths this can be taught, with no reference to application. However this is not ideal. Some (most) people are not good at abstract ideas (I am good at abstraction, but poor at abstract ideas ­— at least in maths).</p>
<p>I remember when I did image processing. I remember the words “it is just the 1d processing, you did in sound processing, but 2d. For a lot of it, it is just done twice, once for x and again for y”</p>
<p>Therefore start with sound processing.</p>
<p>Another Idea is using a texture map. However this may cost a lot to produce these.</p>

CC BY-SA 3.0
2018-01-24T10:28:05.393Z
2018-01-24T10:28:05.393Z
2020-06-18T08:36:57.023Z
ctrl-alt-delor
<p>I'm not (yet) in this situation, so this is a hypothetical question. What would be viable approaches to teaching image processing (IP) and computer graphics (CG) to a blind college student? IP could possibly be approached by explaining images purely as 2D signals, and yet I'm not sure about how effective that would be. CG seems like an even harder task.</p>

CC BY-SA 4.0
2018-06-28T19:30:09.813Z
Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/79519/discussion-on-question-by-rcpinto-how-to-teach-image-processing-and-computer-gra).
thesecretmaster
CC BY-SA 4.0
2024-03-18T01:00:33.073Z
Let's not do the theory of the empty set.
AlMa1r
<image-processing><accessibility>
How to teach image processing and computer graphics to a blind student?
# How to teach image processing and computer graphics to a blind student?

(Asked by: username_0 on 2018-01-23)

I'm not (yet) in this situation, so this is a hypothetical question. What would be viable approaches to teaching image processing (IP) and computer graphics (CG) to a blind college student? IP could possibly be approached by explaining images purely as 2D signals, and yet I'm not sure about how effective that would be. CG seems like an even harder task.

**Tags:** image-processing, accessibility

> **Comments:**
> **username_1**: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/79519/discussion-on-question-by-username_0-how-to-teach-image-processing-and-computer-gra).  
> **username_2**: Let's not do the theory of the empty set.  

---

## 3 answers

### Answer by username_5 on 2018-01-24. Score: 6

I think you can teach 2D graphics using a tactile approach on a phone or tablet.

Students are very likely to be used to tracing their fingers over a mobile device (I have watched awesome videos of blind iPhone users in action).

So position and shape change of an object could be detected by them dragging their fingers over to get auditory feedback at the edges. Ideally you want a truly tactile surface but I don't know of any such devices. I have my own reasons for wanting a computer-controlled version of [one of these](https://rads.stackoverflow.com/amzn/click/B004N7HEYG) [![nail picture toy](https://i.sstatic.net/kduJ9.jpg)](https://i.sstatic.net/kduJ9.jpg)

For actual image processing maybe map colours to tone, so as they move their finger over an image they hear a tone vary depending on the average pixels underneath. Then, as transforms are applied, the tones would change. You could possibly teach colour theory by varying the mapping to only one channel of RGB.

**Update** in one of those great examples of synchronicity, a few days after writing the above I was listening to [Matthias Tretter of MindNode on a podcast](https://www.swiftbysundell.com/podcast/12) mention how he had been convinced to add accessibility to MindNode, a *visual mindmapping product* by a blind user.

His [blog posting](https://mindnode.com/news/2016-06-29-making-mindnode-accessible) has videos showing VoiceOver in action. This is a bit tangential to the original answer but a nice anecdote about how preconceptions about the intended purpose of a tool as being visual doesn't rule it out for blind users.

> **Comments:**
> **username_1**: This is a very interesting idea. Thanks for taking the time to answer, and welcome to [cseducators.se]!  
> **username_6**: This gave me some ideas: The solitaire game with the jumping marbles, but as a grid https://cdn.pixabay.com/photo/2016/03/31/18/35/solitaire-1294487_960_720.jpg Tactile touch screen (may be not available yet) https://i.ytimg.com/vi/JelhR2iPuw0/maxresdefault.jpg  

---

### Answer by username_6 on 2018-01-24. Score: 2

# Just some ideas

I imagine that the biggest problem, may be motivation.

It can be all done abstractly: in maths this can be taught, with no reference to application. However this is not ideal. Some (most) people are not good at abstract ideas (I am good at abstraction, but poor at abstract ideas ­— at least in maths).

I remember when I did image processing. I remember the words “it is just the 1d processing, you did in sound processing, but 2d. For a lot of it, it is just done twice, once for x and again for y”

Therefore start with sound processing.

Another Idea is using a texture map. However this may cost a lot to produce these.


---

### Answer by username_3 on 2018-03-15. Score: 1

A computer is *blind* conceptually speaking. Even if you gave it a camera, it cannot "see" per se. It has a translation of what is viewed to bits.

Now to the blind student. Image Processing is similar to how folks without sight process things - they "feel" their environment for "signals" and make a conclusion about what it is.

A computer does the exact same thing, but with math. Ask them to feel a stick. Easy. Now draw the stick on the floor/paper and ask them to say if a stick or triangle exists on the paper. Really hard. Ask them how would *they* know *if* a triangle is on the paper. Feel the edges? Anything else? How about everytime there's a triangle a new sound is heard? Be creative.

Now talk to them about "rasterization". Think of handling them one sliver at a time, and if anything is different by feeling, they note it. Can they "conclude" a triangle after seeing various cuts of the paper?

This exercise can be naturally extended to Image Processing and then math can be explained.

Computer Graphics is different. It lives in the visual plane and the idea is to "draw" it. A good introduction is this:

*Problem statement: Draw a line on a graph/matrix and each "cell" must be filled in. Which cells to fill in between points A and B when "drawing this line".*

Extending this to blind students could be done with toys/pins etc., How would they know which spots to "fill in" to get as straight a line as possible? What does a "straight line mean"?

This discussion could lead to things about using a line's slope (i.e., math) to figure which pixels to color on a raster display. Same thing with Circles.

I'd start here first. Once that's done, to move to transformations - moving things in space. Easy to feel and then take to the math.

I haven't worked with the blind, but I imagine such exercises/parallels with their sensory world could be useful.

> **Comments:**
> **username_4**: This seems not dissimilar from braille, actually.  
> **username_3**: Conceptually. However, what you want the student to grasp is the connection between sight and math as similar to brain and braille. It’s not that much different. You want the student to *think* how to get it done and what one needs to know/learn for that to happen. Appealing to that knowledge center fosters learning a lot better IMHO.  

---

