How to draw a sine wave in image

I want to draw a sine wave in image and i want to save this image without plot. Because i cant save image with plot function as i want.

[Stephen23]

@umut: an image is just an array of numbers. There is nothing stopping you from changing some of an array's values, following any curve you wish. You do not need to plot anything to do this.

Answer 1

[Guillaume]

Simply calculate the coordinates of the pixels you want to set according to your equation. e.g:

img = zeros(200, 600);  %demo image
numperiods = 8;
amplitude = 50; %pixels
offset = 100;

x = 1:0.25:size(img, 2);  %pixel subsampling for better resolution
y = sin(x*2*pi/size(img, 2)*numperiods)*amplitude + offset;
img(sub2ind(size(img), round(y), round(x))) = 1;
imshow(img);

[umut]

thank you for answer, what should i do to apply a thicker wave ?

[Image Analyst]

Call imdilate(img, ones(9)) to thicken it by 9 pixels.

[umut]

sorry sir i asked so many question but this function thickens both letters and waves. I just want to thicken wave.

[Guillaume]

• Create a new image the same size as your letter image
• Draw the wave onto that new image
• imdilate that new image
• use that image as a mask to set pixels to 1 in your letter image

That last step is:

letterimage(logical(waveimage)) = 1;  %assuming an image of type double