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People often ask, where to put cameras in monoculars
Let’s find out!
Where to Put Cameras in Monoculars?
The answer depends on what kind of monoculars you have. If it is binocular, then you can place the camera anywhere you want. However, if it is a monocular, then you need to consider the focal length of the lens.
In general, the longer the focal length, the wider the field of view. So, if you have a long focal length, then you can place your camera anywhere you want.
But if you have a short focal length, then you cannot place your camera anywhere you wish. You must keep the camera close to the eyepiece of the monoculars, otherwise, the image quality will suffer.
Calibrate a Monocular Camera
A monocular camera (also known as a single camera) is a common kind of vision sensor used in autonomous vehicles. It can be mounted on an ego car to sense objects, detect lane markings, and track objects through the scene.
To start using the webcam, you need to calibrate it first. Calibrating the webcam means finding its intrinsic and extrinsic properties by taking pictures of a special pattern called a “calibraÂtion pattern.” Once you’ve calibrated the webcam, you can then create a model of it.
Estimate Intrinsic Parameters
For estimating the intrinsic (intrinsic) properties of a monocular (monocular) digital single lens reflex (DSLR) or mirrorless interchangeable lens cameras (MILCs), use Computer Vision Toolbox functions and an image of a checkerboard.
Use the function if the camera has standard zoom (or fixed) lenses.
If the lens has a standard focal length, use the
If the image sensor has a fish eye lens, then you should be able to get an accurate measurement using the estimateFishEyeParameters method
If the camera has a fisheye lens then you should be able to see everything clearly.
If you want to get a clearer picture of the results, use the single-camera calibrator application. To set up the device for calibration, prepare the checkerboard, and learn about calibration techniques, see Using Single Cameracalibrator Application.
Place Checkerboard for Extrinsic Parameter Estimation
For a monocular (single) lens attached to a vehicle, the extraneous (extension) parameter defines the mounting position of that single lens. These extraneous (extension), or extra, the parameter includes the rotation angles of the lens with respect to the vehicle coordinates and its elevation angle from the horizontal plane.
To get the extrinsic calibration right, you first need to take a picture of a checkerboard using the camera. Then use the same checkerboard to calibrate the intrinsic parameter estimates.
A checkerboard has an X-Y coordinate system (X-axis pointing to the right, Y-axis pointing down). The checkerboard’s starting point is its lower-right corner.
To place the checkerboard pattern correctly, the X and Y axes of the checkerboard must be aligned with the X and Y axes in the vehicle’s reference frame.
In the vehicle’s reference frame, the X- and Y-axes point forward from the vehicle and to the right, respectively. The origin is at the bottom of the image plane, which is located directly above the vehicle’s front axle.
You can choose between horizontal and vertical orientations for the pattern.
Horizontal Orientation
When placed horizontally, the checkerboard patterns are either on the floor or at an angle perpendicular to the floor. You can place them in front of the car, behind the car, or on the left and right sides of the car.
Vertical Orientation
When placed vertically, the checker board design is perpendicular to the ground and can be placed either in the foreground, background or on the left side of the right side of a vehicle.
Estimate Extrinsic Parameters
Once you place the checkerboard in its desired position, take a picture of it using the monocle. Then, use the EstimateMonoCamParams() method to calculate the extrinsic parameter values. You need to provide these values when calling the EstimateMonoCameras() method.
Camera intrinsic parameters
The key points detected by the algorithm in this example are the four corner points of each square.
The world points of a checkerboard
The height of the checkered pattern’s origins above the ground
For example, for image I and intrinsic parameters intrinsics, this function estimates the extrinsic parameter. By default, estimateMonocameraParameters assumes that the cameras faces forward and that the checker’s board pattern has a horizontal orientation
To improve the estimation accuracy of these parameter values, take multiple pictures and then calculate their averages.
Configure Camera Using Intrinsic and Extrinsic Parameters
After estimating the intrinsic and extrinsic parameter values for the stereo cameras, you can use them to create a monocular depth estimation algorithm. Here’s an example of how to create one using OpenCV.
Where to Put Cameras in Monoculars?
FAQs
What is a monocular camera?
A monocular camera (also known as an eye camera) is a common kind of vision sensor used in autonomous vehicles.
What are the intrinsic parameters of a camera?
Intrinsic properties of a camera include its focal length and optical center.
What are the intrinsic parameters of a monocular camÂera?
These parameters include the rotations of the cameras with respect to the vehicles’ coordinate systems and their heights above the ground.
What is the checkerboard pattern?
The checkerboard uses a pattern-based coordinate system (Xp, Yp) where the Xp-axis point to the right and Yp-axis point down.
Where should I place the checkerboard pattern?
You can place the pattern in front of the vehicle, in the back of the vehicle, or on the left or right side of the vehicle.
How do I use the function?
You need to provide the following values for the Monocular Camera Calibration feature: Intrinsic camera parameters (the intrinsic parameters of the camera). Keypoint locations in the image. The height of the checkers’ origins above the ground.
For instance, for image and intrinsic parameters intrinsic, the code below estimates the extrinsic parameter.
Conclusion
We hope that this guide has been useful. If you have any questions, please let us know in the comments section below.
