Distortion correction of fish-eye lens
Fish-eye lens distortion correction aims to reduce or eliminate the image distortion effect caused by fish-eye lenses. When correcting the distortion of the fisheye lens, the core was to solve a "good" remap matrix, which rearranged some of the original image's pixel-points (or intervening points) and "pieced" them into a rectangular image."Good" was linked to the final requirement, and different tasks often used different correction/distortion solutions. For example, in the smart security industry, whether it was a monocular camera or a monocular camera, the images captured would have distortions, which was the same as the distortion correction principle of a fisheye camera. For monocular cameras, in order to obtain the corresponding relationship between the camera's coordinate system and the three-dimensional world coordinate system, the barrel distortion and pillow distortion of the camera needed to be corrected. For binocular cameras, in order to do epipolar line alignment and realize depth estimation, the output of the two cameras needed to be transformed into the same coordinate system. Teacher Zhang Zhengyou's chessboard correction method estimated the internal and external parameters and distortion coefficient of the camera through the position coordinates of the marker, and then calculated the remap matrix. This method had a good correction effect for monocular and binocular cameras. In terms of practical operations, fisheye correction can also be performed using python language (only relying on the opencv-python package and numpy package), and fisheye distortion correction can also be performed from code examples such as PILimport Image. In addition, the distortion correction function based on digital image processing was also applied to the fisheye lens correction. This solution required rearranging the arrangement of the elements, but for the ultra-wide system where the edge image quality itself was a big problem, it might lead to the image quality of the most edge area being worse. Some equipment would use the image field redundant design and the sensor to perform the redundant matching of the elements to reduce the side effects of the digital correction. Read more exciting novels for free
The perspective distortion of the camera lens
The perspective distortion referred to the change in relative size and position between objects in the shot. Its main characteristic was "near big, far small". For example, when shooting a road, the distant road would get closer and closer to finally converge into a point. Similarly, the closer the lens was to the subject, the larger the subject appeared. The further away from the subject, the smaller the size change in the appearance of the subject. For example, train windows, the change between the windows closer to the lens was obviously larger than the change between the windows far from the lens. The change in size between the windows was smaller the further back. The perspective distortion was only related to the shooting distance and had nothing to do with the focal length. However, in actual shooting, in order to maintain the same size of the subject, different focal length lenses needed to adjust the shooting distance, which would cause differences in perspective distortion. Generally speaking, a wide-angle lens needed to be shot close to the subject, so the perspective distortion was large. A telephoto lens needed to be shot far away from the subject, so the perspective distortion was small. A short focal length (such as 18mm) would produce a wide perspective, and the objects in the picture would appear to be far away, resulting in strong perspective distortion. This distortion was more obvious when shooting buildings with straight lines; a long focal length (such as 200mm) could eliminate or reduce perspective distortion, making the objects in the picture more realistic. In addition, different shooting methods and equipment would also affect the perspective distortion. For example, using a large frame shiftable camera and shiftable lens to shoot could effectively prevent perspective distortion; finding a suitable height to shoot to ensure that the camera lens was parallel to the vertical line of the building to avoid building distortion; post-adjustment could also deal with perspective distortion. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What are the characteristics of fish eye lens in cartoon?
Fish eye lens in cartoons often creates a distorted and wide-angle view. It can make objects appear curved and give a unique perspective that adds a sense of exaggeration or fantasy.
A phone app with a fish-eye lens effect
There were two mobile phone applications that had a fisheye lens effect. One was Fisheye Cameras.(English name: Fisheye Plus Pro). It allowed the iPhone to have a digital simulation of a 170-degree wide-angle and an amazing fisheye lens. It also had a real-time fisheye viewfinder, simulated film replacement, lens, and ring flash. It supported five lenses, seven color ring flashes, and 22 effects. It gave a deeper three-dimensional sense and presented a completely different field of view. However, before using it, one had to go to the App Store to review it to fully unlock it. It was easy to flash back when using it. Especially when choosing the mode, color, and filter, the photos imported from the album couldn't be saved directly. Only the photos taken by the camera could be saved with one click. The other was the Fisheye lens app. The user could change the lens they liked during the shooting process. It was simple to operate. With just one click, they could take a funny photo with a big eye effect. It was powerful and had a delay function. It was very convenient to cut, add text or filter when editing photos. There was also a rich material library with many filter effects. When shooting, you could choose beauty effects. The modes were diverse. You could change the lens according to different scenes and needs. You could also adjust the photo parameters online at any time. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Which software has a fish-eye lens?
The POCO camera had a built-in fish-eye lens. In addition, there was a special fisheye lens app that allowed users to use a fisheye filter to take photos with a fisheye effect. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to use the lens distortion plug-in
The following is how to use the software lens distortion plug-in: - In PS, the lens distortion could be corrected and repaired through the lens configuration file or manual adjustment. - In Unreal Engine 4.24, you can use the "Opencv Lens Distortion" plug-in to correct lens distortion. The steps are as follows: - Open the Plugins window, search for "Lens Distortion", enable the "Open LV Lens Distortion" plug-in, and restart the project. - To simulate or correct the camera distortion, you first need to perform a camera correction to calculate the camera's internal parameters (the camera's internal parameters mainly include the radius and the thickness of the distortion, the vertical and horizontal focal lengths, and the position of the optical center on the final image). The plug-in is based on the default camera correction method of the Open CVs, Zhang Zhengyou's method. It provides two methods of calibration. One is to use a picture file for calibration. That is, a set of pictures containing checkerboards (the combination of checkerboards must basically cover the entire picture and the picture must be clear) is input to the Calibrator. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Target camera lens correction
The lens correction was mainly used to correct the image distortion caused by the optical characteristics of the photographic lens, including geometric distortion (barrel or pincushion-shaped distortion), color difference (colored edges), halo (image edge darkening), etc. Here are some ways to correct the lens: - Turning on automatic lens correction in the camera settings menu could alleviate the problem of the curved distortion around the wide-angle end of the entry-level camera lens. - In Photoshop, you can use the lens correction filter. Its usage and techniques were as follows: - This filter is only applicable to specific images. It is recommended to perform this filter after converting the layer. If the image contains relevant data, you can try the auto-correction function, which will automatically adjust the distortion according to the camera and lens configuration file. If the auto-correction effect is not good or the image does not contain relevant data, you can manually adjust the degree of correction. - You can save the settings in the lens correction for other images taken with the same camera, lens, and focal length. After the correction, the blank transparent area could be filled using the relevant tools or the generation filling technique. - The left side of the filter options provided a series of tools to assist in the correction: - Remove the Distortion Tool and drag directly on the image to increase or decrease lens distortion and correct barrel or pincushion-shaped distortion. - Straighten Tool, which adjusted the angle of the image by drawing a straight line that should be horizontal or vertical in the image. - The Move grid tool, usually used with the correction grid, can move the entire correction grid. - The Hand Tool and the Scale Tool were operated in the same way as the ones on the toolbox. - In the "auto correction" tab, the "geometric distortion" could correct the straight line bending problem in the image, and the "Chromatic Aberration" could deal with the color edge problem caused by the lens not being able to focus different colored lights on the same point. - In the ACR, you can also perform lens correction. In the Color sub-panel, you can use the slide bar to repair the edges of objects caused by shooting scenes with strong light and dark contrast or full aperture, and the bright edges of green, purple, and other colors at the junction of light and dark. The third sub-panel of the ACR had two areas,"Upright" and "Manual Alignment." Upright had multiple modes for photo alignment, including disable alignment, automatic correction (full-scale image perspective distortion), only photo horizontal alignment, correction of photo horizontal and vertical perspective distortion, and full alignment (photo horizontal alignment and horizontal and vertical perspective distortion). <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Tenglong lens correction information
Some Tenglong lenses support the built-in lens correction function. For example, Tenglong's top APS-C frame micro-single lens is compatible with the built-in lens correction function of the body; Tenglong 28 - 200mm lens can be easily corrected with Tenglong's lens configuration file; Tenglong B070S 17 - 70mm F/2.8 Di III - A VCRXD lens includes lens correction in the body. In addition, the 70 - 180mm F2.8 Di III VXD lens part of Tenglong had insufficient performance of the floating mechanism used to correct the curvature of the imaging surface. The affected products could be identified through the official website by checking the serial number. Tenglong would provide recalibration or lens replacement services for the affected users. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Canon lens digital correction data
Canon lens 'digital correction data included lens correction parameters such as distortion, color difference, halo, and so on. This data could help the photographer better deal with the relevant problems in the image to improve the quality of the image. Not every Canon lens had aberrations, so it was not necessary to turn on the aberrations correction every time. It was only necessary to correct the photos with obvious aberrations or in specific scenes. Different shooting scenes may require different correction parameters. The reasonable use of lens correction data can make the picture more in line with the photographer's intention. For example, when shooting landscape, portrait, and macro, aberrations correction can improve the quality of the photo. For landscape photography, turning on aberrations correction can improve the depth of field and color reproduction ability. In addition, the lens correction data could help reduce the color difference problem. For example, the application of Canon 1dx lens correction data could improve the overall image quality, allowing the photographer to obtain a more delicate and clear picture, and enhance the artistic sense and appreciation of the picture. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Canon downloads lens correction data
As a Canon camera user, the most convenient and reliable way to download Canon lens correction data was to download the lens correction data from Canon's official website. On Canon's official website's lens correction data download page, you could find the correction data packages for different lens models. You could download the correction data of the corresponding model, and then import it through the camera software to realize the lens correction. To achieve this function, Canon needed to use the lens of the same brand to correct it by transmitting data. When using a Canon camera and a sub-factory lens, the correction data of the sub-factory lens needed to be downloaded and installed in the camera in advance. Generally speaking, each lens had a unique correction data that needed to be downloaded separately. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What is the effect of turning off the lens correction function on the image
If the lens correction function is turned off, the image may be affected as follows: 1. ** Chromatic aberrations **: Chromatic aberrations caused by refraction when light passes through the lens cannot be corrected. When shooting in a high-contrast environment or with a large aperture, it was easy to have purple edges, which meant that the edges of the image might produce purple, blue, and green edges. 2. ** Distortion **: The lens may cause barrel distortion or pillow distortion in the image. When shooting scenes that require straight lines such as buildings, the high-rise buildings in the image may appear to be crooked, and this distortion will not be corrected. 3. ** Vigor **: Whether it's a wide-angle lens (due to geometric optical factors, such as the hood or the light at the edge of the lens being blocked) or a telephoto lens (due to the long focal length, less light enters the small angle of the LCD lens), the vigour produced by the lens will not be corrected, causing the corners of the image to be darker than the center. 4. ** In terms of resolution **: The resolution reduction caused by the refraction phenomenon and the low-pass filter will not be corrected. For example, when shooting with a small aperture, the loss of details caused by light refraction cannot be improved, and the resolution reduction caused by the low-pass filter cannot be corrected. 5. ** Aberration **: The aberrations produced by the lens, such as the reduction of sharpness, cannot be corrected by the lens correction function. The overall sharpness of the image may not reach the effect when the correction function is turned on. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>