# How to Draw Line on Image in Matlab

Ammar Ali Feb 02, 2024

This tutorial will discuss how to draw lines and other shapes on an image using the `plot()` and `insertshape()` function in MATLAB.

## Draw Line on an Image Using the `plot()` Function in MATLAB

If you want to draw a line or other variables like the sine wave on an image, you can use the `plot()` function to do that. For example, let’s draw a line on an image. See the code below.

``````load clown
image(X)
hold on
plot([180 50], [60 250],'Color','r','LineWidth',5)
``````

Output:

In the above code, we have used an already stored clown image and plotted a line on the clown image using the `hold on` command. You can change the color of the line using the `Color` property and the line width using the `LineWidth` property. You can also change the starting and ending point of the line.

## Draw Line on an Image Using the `insertshape()` Function in MATLAB

If you want to draw shapes: line, circle, rectangle, and polygon on an image, you can use the `insertshape()` function to do that. The basic syntax of the `insertshape()` function is given below.

``````Output = insertShape(Image, shape, shape_position)
``````

In the above code, `Image` is the image object on which you want to draw, `shape` is the shape you want to draw on the image, `shape_position` is the position on the image at which you want to draw the shape. For example, let’s draw a circle on an image. See the code below.

``````X = imread('peppers.png');
output = insertShape(X,'circle',[100 100 100],'LineWidth',5);
imshow(output)
``````

Output:

In the above code, we have used an already stored peppers image, and a circle is drawn on the image using the `insertshape()` function. In the case of a circle, the position consists of three values; the first value is the x-axis position, the second value is the y-axis position, and the third value is the radius of the circle. In the case of a rectangle, the position consists of four values, the first value is the x-axis position, the second value is the y-axis position, the third value is the width, and the fourth value is the height of the rectangle. You can also change the color of the shape using the `Color` property, the line width using the `LineWidth` property, and also the opacity in case of filled shapes using the `Opacity` property. Check this link for more details about the `insertshape()` function.

Author: Ammar Ali

Hello! I am Ammar Ali, a programmer here to learn from experience, people, and docs, and create interesting and useful programming content. I mostly create content about Python, Matlab, and Microcontrollers like Arduino and PIC.