Generate gray scale image which contains non overlapping triangle.

Generate gray scale image of M×N having a border around it which contains n-non overlapping right angle triangle.As shown in below figure.Afterwards Image size become M+2*border×N+2*border.

[Rik]

The plan by Amrita Singh to cheat on their homework fails. Here is the question they posted, as retrieved from Google cache (unfortunately without the attached image):

Generate gray scale image which contains non overlapping triangle.

Generate gray scale image of M×N having a border around it which contains n-non overlapping right angle triangle.As shown in below figure.Afterwards Image size become M+2*border×N+2*border.

[Amrita Singh]

Actually the question is not containing full information then also you want to solve you can.

[Rik]

If you think the question is unclear, you should clarify it, not remove it. You received an answer. Explain in a comment why it doesn't solve the problem.

[Amrita Singh]

Yes,I received an answer from image analyst but still it's not clear to me. How to make right angle triangle in a digital image without using Inbulit function(like poly2mask() and patch())

[Image Analyst]

Why do you want to prevent yourself from using the very functions that would allow you to solve this easily?

[Amrita Singh]

Sorry.I only want to solve this problem without using built-in function. If it's possible then you can guide me how to start?I just want to know the technique.

[Rik]

Start by learning C or assembler. That way you can avoid all built-in functions, including plus and subsref.

Do you have a clear description of the functions you want to avoid? And why? To challenge yourself?

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Image Analyst]

Try poly2mask():

binaryImage = false(M, N);
for k = 1 : numTriangles
    x = rand(3, 1);
    y = rand(3, 1);
    thisMask = poly2mask(x, y, M, N);
    binaryImage = binaryImage | thisMask;
end
imshow(binaryImage);

It should be really trivial for you to adapt it to make sure the triangles are right triangles. Just make sure 2 of the x's are the same and 2 of the y's are the same.

[Image Analyst]

I don't know - you'd basically have to write your own version of poly2mask(). But why? Why not use built-in functions? It's just simple geometry so I'm sure with the right equations you could do it, but it's not something I want to spend my Sunday doing for you when you can do it just as well as I can. Good luck though.

[Amrita Singh]

Thanks

[Rik]

A different cache was needed for the deleted comment:

Without using Inbulit function how to create non overlapping triangles?

[Image Analyst]

If you do it on a graph instead of a digital image you could use patch(). From the help, here is there demo for a triangle:

x2 = [2 5; 2 5; 8 8];
y2 = [4 0; 8 2; 4 0];
patch(x2,y2,'green')

Use exportgraphics() or saveas() to save it.

[Amrita Singh]

Thanks for help. Actually the Question contain some missing information.Sorry for that.

[Image Analyst]

Is this homework? If so, I think this is enough information for you to solve it. If not, let me know.

[Amrita Singh]

Still,I doesn't get any helpful resource where i get to know how to make right angle triangle in digital image without using inbuilt function.By making 2 x and y same.It doesn't mean that it's satisfy the property of right angle triangle.

[Image Analyst]

Is this homework?

[Amrita Singh]

Is it possible or not?If yes then how can i start?I just want to learn.

[Image Analyst]

Is this homework?

columns = 800;
rows = 600;
binaryImage = false(columns, rows);
numTriangles = 4;
for k = 1 : numTriangles
	xOffset = 0.7 * columns * rand(1);
	yOffset = 0.7 * rows * rand(1);
    x = 0.3 * columns * rand(3, 1) + xOffset;
    y = 0.3 * rows * rand(3, 1) + yOffset;
    thisMask = poly2mask(x, y, columns, rows);
    binaryImage = binaryImage | thisMask;
end
imshow(binaryImage);

[Amrita Singh]

No, without using Inbulit function(like poly2mask).and i dont need any code...I just want to know the steps how to do this?

[Image Analyst]

See this