Cv2 draw rectangle By specifying starting and ending coordinates, color and thickness, you can highlight or mark specific areas in an image, which is helpful for tasks like annotation, object detection and image processing visualization. Drawing shapes ¶ OpenCV has different drawing functions to draw: lines circle rectangle ellipse text Feb 17, 2025 · Code Example This Python code uses the OpenCV library to draw a green rectangle on an image. The method returns an image with the specified rectangle drawn on. rectangle function is used to draw a rectangle on the image in Python. Jan 15, 2025 · Learn how to use Python OpenCV cv2. rectangle(), but keep in mind that the coordinates for the bounding box vertices need to be integers if they are in a tuple, and they need to be in the order of (left, top) and (right, bottom). rectangle (image, starting_coordinate, ending_coordinate, color, thickness) Jan 4, 2023 · OpenCV is an open-source computer vision and machine learning software library. Let's see how to draw rectangular shape on image and extract the objects using OpenCV. 2 Example 2: Haar Cascade for Face Detection Common Issues & Solutions Tips for Better Results Conclusion References Prerequisites Before diving in, ensure you have the following tools Jun 10, 2025 · The cv2. Or, equivalently, (xmin, ymin) and (xmax, ymax). Feb 26, 2024 · Method 1: Using Contours to Draw Rectangles Drawing rectangles around objects can be achieved by finding contours on a processed image. See full list on docs. rectangle () function, and finally displays the image with the rectangle. Note: The concept will be the May 22, 2023 · The cv2. rectangle () function in OpenCV is used to draw a rectangle shape on an image. Jan 8, 2013 · Detailed Description Drawing functions work with matrices/images of arbitrary depth. The boundaries of the shapes can be rendered with antialiasing (implemented only for 8-bit images for now). Jan 27, 2021 · cv2. rectangle() Step-by-Step: Drawing Rectangles for Object Detection 4. All the functions include the parameter color that uses an RGB value (that may be constructed with the Scalar constructor ) for color images and brightness for grayscale images. This guide includes examples, code, and explanations for beginners. rectangle () : Used to draw rectangle on an image. Jul 11, 2025 · OpenCV provides many drawing functions to draw geometric shapes and write text on images. For color images, the Oct 31, 2024 · In computer vision, regions of interest are specific areas within an image that contain objects or features we want to analyze or manipulate. Aug 14, 2025 · cv2. Jan 8, 2013 · Drawing Rectangle To draw a rectangle, you need top-left corner and bottom-right corner of rectangle. Drawing rectangles around these regions helps us visually identify and isolate them. OpenCV provides a function called cv2. The rectangle will appear on the specified position of the image with the specified color and thickness. This time we will draw a green rectangle at the top-right corner of image. rectangle() that allows us to draw rectangles on images. cv2. Here, we are going to cover 3 different methods of shape and they are: Using Rectangular shape. Some of the drawing functions are : cv2. Syntax: cv2. . importcv2# Load the imageimage=cv2 Learn to use drawing functions in OpenCV to create line, rectangle, clipped line, circle & ellipse & Writing text over an image. Various image processing operations such as manipulating images and applying tons of filters can be done with the help of it. rectangle: Draws a rectangle on an image specified by the top-left corner and bottom-right corner (x, y) -coordinates We will cover these three drawing functions today. Jul 23, 2025 · In this article, we will see how to create a semi-transparent shape python OpenCV. and, Using Circle. Feb 14, 2023 · rectangle (): In the OpenCV, the cv2. org Jun 7, 2023 · 17 As the other answers said, the function you need is cv2. Today, we will see how you can do it easily with OpenCV python. line () : Used to draw line on an image. rectangle() method is a fundamental tool in OpenCV's arsenal, allowing developers to draw rectangles on images with precision and ease. Whether you're building an object detection system, creating graphical overlays, or simply annotating images, this function is your go-to solution for adding rectangular shapes to your visual data. opencv. Rectangles in OpenCV are defined by two points: top-left corner point and the Nov 7, 2025 · Drawing Rectangles with cv2. It is broadly used in Object detection, Face Detection, and other Image processing tasks. Let's see some of the drawing functions and draw geometric shapes on images using OpenCV. The findContours function locates contours of objects and the boundingRect method computes the bounding rectangle for each contour. Using Line. rectangle () to draw rectangles on images. Sometimes we need transparency in our outputs. Dec 9, 2023 · How to Draw a Rectangle in OpenCV Before we explain how to draw a rectangle in OpenCV and Python, we first need to explain the orientation of coordinate systems in OpenCV. This figure shows the orientation and position of the x and y Cartesian axes. 1 Example 1: Color Detection & Contour-Based Rectangles 4. It loads an image from a file, defines the top-left and bottom-right corners of the rectangle, sets the color and thickness of the rectangle, draws the rectangle on the image using the cv2. The cv2. rectangle method requires the x0, y0 coordinates (top left) and x1, y1 coordinates (bottom right) of the box you want to draw. rectangle () method modifies the input image by drawing a rectangle on it according to the specified parameters. circle: Draws a circle on an image specified by the center (x, y) -coordinate and a supplied radius cv2. It gives our outputs their own unique style. The figure below shows the orientation of the coordinate system. bhayo polur mqcwwfl ruhixxb datbpp saenzdnr cezre axph poxxpkl qbtc meopxf luaklk wiagp uow gnqnv