I am MATLAB beginner, and I got stuck because of some error.

I am MATLAB beginner, and I got stuck because of some error.

Error: File: Function1.m Line: 31 Column: 8 (which is very bottom like If R > = Threshold)

Unsupported use of the '=' operator. To compare values for equality, use '=='. To specify name-value arguments, check that name is a

valid identifier with no surrounding quotes.

Also, the End line got an error, too

Line 34: The End operator must be used within an array index expression

How can I fix the errors?

Also, I'm working on an assignment.

If there are mistakes, please let me know/

Task: write a Matlab function that should filter an image to identify the edges and their

orientations (hortizontal, vertical, 45 degree, and 135 degree edges).

Label = 1 for horizontal edges

Label = 2 for vertical edges

Label = 3 for 45 degree edges

Label = 4 for 135 degree (that is -45 degree) edges

Label = 5 for non-edge pixels, i.e. magnitude/response of edge is below a giventhreshold

1. Input: an original image f and a threshold value T;

Output: EdgeImg and IndexImg

2. Pick the four spatial masks H, V, D45, D135 from Note 7 part 1

3. Compute R1 (hortizontal edge), R2 (vertical edge), R3 (45 degree), R4 (135 degree) for the entire image. Hint: use ‘imfilter’. For example:

R1 = imf ilter(f, H)

4. For a pixel at a location (i, j) in the image (you might want to use for loop twice):

(a)

decide in which edge direction the pixel is associated with. For example, if|R2| > Rj for all j = 1, 3, 4, then the pixel is associated with a vertical line. Hint: use [R, ind] = max [R1(i, j), R2(i, j), R3(i, j), R4(i, j)] where R stores the largest response value, ind stores the index/label that is

associated with R.

(b) If the response R ≥ T, then EdgeImg(i, j) = R; IndexImg(i, j) = ind;

(c) If the response R < T, then EdgeImg(i, j) = 0; IndexImg(i, j) = 5; (which is the non-edge index)

Test your function with an image and a threshold value and display both the edge imageand the indexed image.

here is my code

function [EdgeImg, IndexImg] = Function1(InputImg, Threshold)

% Four masks for the entire image

H = [-1 -1 -1; 2 2 2; -1 -1 -1];

V = H';

D45 = [2 -1 -1; -1 2 -1; -1 -1 2];

D135 = [-1 -1 2; -1 2 -1; 2 -1 -1];

% Compute edge strengths and orientations using the four masks

R1 = imfilter(InputImg, H, 'symmetric');

R2 = imfilter(InputImg, V, 'symmetric');

R3 = imfilter(InputImg, D45, 'symmetric');

R4 = imfilter(InputImg, D135, 'symmetric');

%Initial Edgelmg and Indexlmh

EdgeImg=zero(size(InputImg));

IndexImg=len*ones(size(InpuImg));

%Now, loop applied through the pixels at edge using for

for k=1:s(Intlmg,1)

for m =1:s(Intlmg,2)

end

EdgeImg(IndxImg==len)=0;

figure;

subplot(1,2,1,0);

show(EdgeImg,img);

subplot(1,2,2,0);

show(IndexeImg,img);

end

[R,jip] = maximize([R1(k,m),R2(k,m),R3(k,m),R4(k,m)

If R > = Threshold

EdgeImg(k,m)=R;

IndexImg(k,m)=jip;

end

Answer 1

[Garrett Fullerton]

Hey! A greater than/equal to comparison in MATLAB is done using the ">=" symbol. Your code has a space in between the ">" and "=" symbols, and MATLAB is returning an error because it's interpreting the two symbols separately. I would try removing the space and see if that solves your error.

If R >= Threshold

EdgeImg(k,m)=R;

IndexImg(k,m)=jip;

end

[Stephen23]

Also MATLAB does not have an If operator. However it does have an if operator:

https://www.mathworks.com/help/matlab/ref/if.html

[Yojp21]

Thank you for the quick answer and I fixed my code, but, unfortunatelly I got other error.

I have no idea what it means

Error message

Not enough input arguments.

Error in Function1 (line 15)

R1 = imfilter(InputImg, H, 'symmetric');

Here is my updated code

function [EdgeImg, IndexImg] = Function1(InputImg, Threshold)

% Four masks for the entire image

H = [-1 -1 -1; 2 2 2; -1 -1 -1];

V = H';

D45 = [2 -1 -1; -1 2 -1; -1 -1 2];

D135 = [-1 -1 2; -1 2 -1; 2 -1 -1];

% Compute edge strengths and orientations using the four masks

R1 = imfilter(InputImg, H, 'symmetric');

R2 = imfilter(InputImg, V, 'symmetric');

R3 = imfilter(InputImg, D45, 'symmetric');

R4 = imfilter(InputImg, D135, 'symmetric');

% Initial Edgelmg and Indexlmh

EdgeImg = zeros(size(InputImg));

IndexImg = len * ones(size(InputImg));

% Now, loop applied through the pixels at edge using for

for k = 1:size(InputImg,1)

for m = 1:size(InputImg,2)

[R, jip] = max([R1(k,m), R2(k,m), R3(k,m), R4(k,m)]);

if R >= Threshold

EdgeImg(k,m) = R;

IndexImg(k,m) = jip;

else

EdgeImg(k,m) = 0;

IndexImg(k,m) = 5;

end

end

end

figure;

subplot(1,2,1);

imshow(EdgeImg);

title('Edge Image');

subplot(1,2,2);

imshow(IndexImg, []);

title('Index Image');

end

[Stephen23]

"I have no idea what it means"

How are you calling the function? How many input arguments did you provide when you called it?