Equirectangular projection formula calculator python On average we, as humans, can see about 180° I have this image : I don’t know exactly what kind on projection it is, I guess equirectangular or mercator by the shape. But I have no idea how to performance this projection by OpenCV. In this cube I do rotations around it's origin and create images using glReadPixels. It's a equirectangular projection of a room and have a 2:1 ratio. mp4 (any GoPro) or . In this cube I do rotations around it's origin and create images using glReadPixels. 10 from the OpenGL 4. I'm trying to convert a lat/long point into a 2d point so that I can display it on an image of the world-which is a mercator projection. Converts between the equirectangular and mercator projections. dot(y, y) for the vector projection of x onto y. ; s is the sample standard deviation. Basically this is the Pythagorean theorem. In particular, the plate carrée has be- The following describes a tool for extracting an ideal, pinhole camera style perspective projection from an equirectangular (also called spherical) projection. To get in touch with me you can message me on LinkedIn, Twitter, or YouTube. With that background information out of the way, let's move straight into our first application of the spherical coordinate system: the Equirectangular Projection. So, assuming that the cubic image has a height h_o and width w_o, the equirectangular will have a height h = w_o / 3 and a width w = 2 * h. Find and fix This utility extracts a perspective projection from a set of 6 cube maps images. Code With an equirectangular projection, the mapping is direct and linear. Examples of Vector Projection: Projection of One Vector onto Another: Use the formula to find the projection of vector A onto vector B. For reference codes of the most commonly used projections, see spatialreference. I have found multiple questions regarding fisheye → equirectangular conversion, in this and other forums. Navigation Menu Toggle navigation. If [Tex]\vec A[/Tex] is represented as A and [Tex]\vec B[/Tex] is represented as B, the Vector Projection of A on B is given as the product of A with Cos θ where θ is the angle between A and B. As of 2024, is there really no built-in OpenCV functionality that performs this conversion in simple steps, without manual implementation? The documentation A few years ago, I was working with equirectangular projections of spherical data (mostly spherical panoramas and spherical depth maps) for a 3D reconstruction research project. Equirectangular Projections. Check it out on on GitHub! We will start with the very straightforward Plate Carrée (also known as Equirectangular or Equidistant Cylindrical. Or you can find a formula to go directly from azimuthal -> mercator. Usage. Usage (1) Mercator and Equirectangular are two different map projections. Sign in Product GitHub Copilot. --nearest: Use nearest sampling for stretching that will occur due to change of aspect ratio. Equirectangular Projection is the representation of a spherical surface by uniformly sampling it in longitudinal and latitudinal angles. ‑‑to_equirectangular: Convert the image to the Equirectangular projection. The scripts used to convert the source images into the equirectangular images were produced in Python and my VR app runs on iOS using Objective-C. This introductory text is modified from a tutorial on working with geospatial data using the library cartopy that was presented at the 2018 Scipy conference by Phileas Elson (lots of great things Python script to map an equirectangular (cylindrical projection, skysphere) map into 6 cube (cubemap, skybox) faces. 360 (MAX only) files into single frames with correct metadata. ; t is the critical value from the t-distribution based on the desired confidence level and degrees of freedom (df=n−1). R_u = f*tan(theta) and the projection by common fisheye lens cameras (that is, distorted) is modeled by. I wrote the code to be numpy-friendly. 1. A blazing fast, shader based image projection converter. Now for each pixel (x, y) 0 <= x <= w, 0 <= y <= h in Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company With the algorithm below, when the projection plane is tangent to the equator (the center line of the equirectangular image), projected image looks rectilinear. 6. Now I know I can calculate (x,y) like this: x = ((lon + 180) * (map Answering my own question with these two Python functions: def lon2x(lon, w): return int(img_w I am trying to transform an equirectangular projection to an azimuthal projection with python. Regarding Python, the following modules are used: cv2 : CPU-Only OpenCV for Python. Perpective. How do I project this now on a 1366x768px browser screen? Equations and code behind conversion between equirectangular images and cubemaps. 3 Map Projections¶. imagemagick ffmpeg streetview panorama mapillary panorama-image equirectangular-panorama equirectanguar-projection equirectangular equirectangular-images panoramic So, I found a solution mixing this article on spherical coordinates from wikipedia and the Section 3. Azimuthal equidistant Great circles look like, well, circles on a sphere – but project them on an equirectangular surface, and voila! You get yourself nice curve just like the horizon ones in the photos above. Goal: Introduce the concepts of projecting 3D spherical geography onto a 2D plane. The resulting equirectangular projection is as follows. Each camera has been calibrated independently and the extrinsics between the two * cameras is assume to be known. Looking back at our definitions of our coordinates X and Y we can see that they are defined with x = np. Examples of projections that preserve distances along meridians (but not parallels): Equirectangular / Plate Carree. Elimination of The same thing applies to the azimuthal projection: You can go from azimuthal coordinates -> equirectangular -> mercator and sample the image. It’s all about defining the correct transformation maps for OpenCV. Compatible with cuda tensors for faster processing. I have a 13312 px width and 6656 pixel height Panorama picture. GLSL. We again got two new shapefiles for data in equirectangular projection. Haversine is common but there is not a "standard" formula. Projector 3 — Map Projection Explorer User's Guide: List of Map Projections Following is a list of the map projections that may be viewed and saved by G. Its aspect Python implementation of convertion between equirectangular, cubemap and perspective. A blend region of 10 degrees is used, for this example the command line might be It is important to run the optimisation on a visually rich scene, the metric the algorithm uses is Converting from cylindrical projections to cube maps. I invite you to look at the wikipedia page on Haversine formula if you want to explore other methods. meshgrid(x, y), if you run print(X);print(Y) you will see that the center of the upper left hand corner should be located at ( I am using a formula to calculate the distance between two coordinates. Once I have processed those images I get a few points per image for which I would like to Convert the given cubemap to equirectangular. (equirect2cube, cube2equirect, equirect2perspec) - sunset1995/py360convert (equirect2cube, cube2equirect, equirect2perspec) - sunset1995/py360convert Converts between the equirectangular and mercator projections. Direct Polar, known as Spherical or Equirectangular Projection The reason is that, even though there is a very simple mapping between equirectangular projection and cubic projection, the mapping between the areas is not simple: when you establish a correspondence between a specific point of your destination image and a point in the source with an elementary computation, as soon as you convert both points to 1. See also sphere2cube . pi) y = 1440 - (altitude * 2880 A few years ago, I was working with equirectangular projections of spherical data (mostly spherical panoramas and spherical depth maps) for a 3D reconstruction research project. I saw this formula on Wikipedia and it works perfectly for my use case. Converts GoPro . Can be used via a CLI or directly in Python. Let us conviniently determine the height of the projection window as 2 which means the width is exactly twice the aspect ratio (see the above equation). One of these is the Hammer projection that represents projects the full 360x180 degree A CRS tells Python how those coordinates relate to places on the Earth. Snyder’s selection guideline and on the extension 🌎→🗾Equirectangular (360/panoramic) image processing library for Python with minimal dependencies only using Takes 2 raw fisheye GoPro Fusion frames and converts them to a more widely recognised equirectangular projection. A great circle is the intersection between a plane and a sphere if Python script to map 6 cube (cubemap, skybox) faces into an equirectangular (cylindrical projection, skysphere) map. Does someone know a python solution to get the Azimuthal projection from an Equirectangular o from an Vector Projection Formula. (equirect2cube, cube2equirect, equirect2perspec) Fast and Simple Equirectangular Rotating python code 😎. width / 360 ) * azimuth Azimuth = Phi = Heading = Angle to the left or right. @ashleedawg - The Haversine formula is a particular method for estimating distance between two points assuming Earth is a sphere. I am attempting to calculate the bearing between two lat/long. I study a lot of resource on the internet. From the formula I´m new to python and using scripts in general but do need to use the script below to convert 6 images to equirectangular. 🌏. Once I have processed those images I get a few points per image for which I would like to calculate their equivalent coordinates on the equirectangular panorama image. by Marinus of Tyre. The left fisheye above mapped into equirectangular space is shown below, it fills more than half the equirectangular image because the lens is 210 degrees. How does one A blazing fast, shader based image projection converter. Multiply the resulting scalar by vector B to obtain the projection of A onto B. Split panorama into perspective view with given parameters. Looking at each pixel in our UV texture, we represent its position along the u-axis as an azimuth angle on the unit sphere. The Projection Wizard is based on John P. Google Maps and Microsoft Virtual Earth use a Mercator projection based on the World Geodetic System (WGS) 1984 geographic coordinate system Haversine formula in Python (bearing and distance between two GPS points) 5. gopro fisheye equirectangular equirectangular-images equirectangular-projection Updated Aug 15 , 2023; C It should therefore be possible to merge the two fisheye images together to form a complete equirectangular projection, which defines the whole visible world. The example here will eventually lead to a more complex model where we build a mortgage calculator in Python. org. I want to draw a orthographic projection, b or maybe a General Perspective projection (which one looks better) of it according to a direction vector defined by two angles (heading and pitch). As of 2024, is there really no built-in OpenCV functionality that performs this conversion in simple steps, without manual implementation? The documentation I completed stitching using six images obtained by rotating in place using Python stitcher class. It is consistent with the conventions here: Converting an equirectangular image to a perspective projection and here: Converting to and from 6 cubic environment maps and a spherical projection As an example consider the 6 cube faces presented below. - Xyene/cube2sphere. gdal_rasterize -b 1 -b 2 -b 3 -burn 40 -burn 40 -burn 220 \ -l dst1 dst1. In reality it takes any 2D image and treats it as it were a cylindrical projection, conceptually mapping @LloydRayner if you find my answer useful, you may upvote and/or accept it, why your point cloud look "sliced" -- I don't know, it's unlikely to be a problem of open3d package -- I use that quite a lot. 8. I am trying to transform an equirectangular projection to an azimuthal projection with python. (2) Mercator and Equirectangular formula each has two forms - one for ellipsoid, and one for sphere. tif The only The map projection having transformation equations x = (lambda-lambda_0)cosphi_1 (1) y = phi, (2) and the inverse formulas are phi = y (3) lambda = lambda_0+xsecphi_1, (4) The following table gives special cases of Equirectangular to Pinhole; Fisheye to Pinhole; Example Code /** * Demonstrates how to combine multiple images together into a single view. Converts between the equirectangular and mercator Prerequisites For Python Loan Calculator Project Python and Tkinter Installation: Tkinter is a standard Python library for GUI development and usually comes bundled with Python. R_d = 2*f*sin(theta/2) You already know R_d and theta and if you knew the camera's focal length (represented by f) then cube2sphere is a Python script to map 6 cube (cubemap, skybox) faces into an equirectangular (cylindrical projection, skysphere) map. The Equirectangular Distance Approximation provides a simple and fast way to estimate distances but may lack precision for long distances due to the distortion introduced by the projection. I have found py360convert, which allows convert from equirectangular to cubemap, from which it should be easier to obtain an azimuthal projection. 2024. - Xyene/sphere2cube Where: xˉ is the sample mean. e. import os import cv2 import Equirec2Perspec as E2P if __name__ == '__main__': equ = E2P. sys : Access to system variables and functions from the interpreter (usually comes with Python) PIL : Python Imaging Library, used for image file manipulation. For a reason I can’t remember, I started wondering what a great circle would look like in an equirectangular projection. numpy : Tools for scientific computation, used for its fast n-dimensional arrays. eqruirect2persp (img, FOV, Theta, Phi, Hd, Wd) Parameters img – input cubemap image FOV – field of view (in horizontal direction) Theta – Viewing angle wrt z axis The equirectangular projection was used in map creation since it was invented around 100 A. ) We pass an instance of the projection class to the projection keyword argument of Figure. See Mathworld's page for more detailed information on the mathematics of this projection. In this tutorial, we are going to learn how to build a simple cashflow projection model in Python. (equirect2cube, cube2equirect, equirect2perspec) Conversion between Equirectangular and planar: Pure python implementation and depend I have create a simple cube and textured it with a cubemap extracted from a panorama image. Parameters: cubemap: Numpy array or list/dict of numpy array (depend on cube_format). From the formula In this section, we introduce the two common projections for the spherical image, i. Because of the distortions in-troduced by this projection, it has little use in navigation or cadastral mapping and finds its main use in thematic mapping. The sampling grid is rectangular, in For more on equirectangular projection, both Wikipedia and Wolfram Mathworld are quite useful. mode:str: I am trying to calculate distortion so I can distort overlaying text and forms to precisely match an image of an equirectangular projection. 0, along with alternative names and An equirectangular projection of the Earth; the standard parallel is the equator. Both OpenCV code or Mathematica formula a The equirectangular projection was used in map creation since it was invented around 100 A. Python implementation of convertion between equirectangular, cubemap and perspective. What is an equirectangular image? Converting equirectangular image to fisheye image It is a method of representing the curved spherical 3D world on a 2D plane in the form of longitudes and latitudes. Rasterization is almost the same as in the previous case. Panorama. Commented Apr 3, 2014 at 15:20. height/2), lines are warped. To obtain vector projection multiply scalar projection by a unit vector in the direction of the vector onto which the first vector is projected. The following maps a cylindrical projection onto the 6 faces of a cube map. R_u = f*tan(theta) and the projection by common fisheye lens cameras (that is, Prerequisites For Python Loan Calculator Project Python and Tkinter Installation: Tkinter is a standard Python library for GUI development and usually comes bundled with Python. I've seen various ways of doing this and a few questions on Example code for equirectangular to perspective conversion fisheyeUtils. Probably taking a look at The apsect ratio is calculated as follows: ar = screen width / screen height. Verify its presence, or install it using `pip install tk`. Supports 360 Developed using Python>=3. I use following formular to calculate the xPosition: var xPosition = ( panorama. --to_mercator: Convert the image to the Mercator projection. I've seen various ways of doing this and a few questions on stack overflow-I've tried out the different code snippets and although I get the correct longitude to pixel, the latitude is always off-seems to be getting more reasonable though. The Haversine Formula, considering the Earth as a sphere, offers better accuracy than the Equirectangular method but still simplifies the Earth’s shape Because all Equirectangular projections are affine transformations of this one (where the x-coordinate is the longitude and the y-coordinate is the latitude), and affine transformations of sine waves are still sine waves, we cannot expect any geodesics in any form of the Equirectangular projection to be sine waves (except for the Equator, which plots as a horizontal line). [1] The projection The Equirectangular Distance Approximation provides a simple and fast way to estimate distances but may lack precision for long distances due to the distortion introduced by the projection. 10. Home Projects Map projection converter 2024 Python GLSL GitHub page A blazing fast, shader based image projection ! This is effectively the same as equirectangular in the horizontal axis, but compresses the vertical axis close to the poles (which might not be desirable for texture mapping, since it will tend to cause loss of detail there. Indeed, the poles themselves can't be represented (except at infinity). All answers proposed/explained how to implement it from scratch, mostly relying on Paul Bourke’s tutorial. Map projection converter. I know this is a equirectangular projection. Hot Network Questions Would Europeans be effective slaves on Caribbean Plantations? Converting fisheye image to equirectangular image¶ The python version of the code is inspired by this repository. D. I have a piece of a map in equirectangular projection. Interpreting the Result: In addition to equirectangular projectiosn, there are of course a whole range of other projections that can represent wide fields of view, including the full sphere. w: Output equirectangular width. Disregard equation alignment in one line The description you mention states that the projection by a pin-hole camera (one that does not introduce lens distortion) is modeled by. Both OpenCV code or Mathematica formula a I am trying to reproduce in Python a coordinate transformation of a map from Mollweide coordinates (see Figure A) to Equirectangular coordinates (see Figure B) that I saw done in Mathematica in the Python 3. It's the texture for an attitude indicator, b. You can rotate equirectangular images by rotating the surface of a sphere. ; n is the sample size. A 360 camera was used to generate * the two input fisheye images. a geographic (Plate Carrée) projection, which is based on an equal latitude- longitude grid spacing (not an equal area projection!) Looking it up in wikipedia it turns out that this is also known as an equirectangular projection. The real-time way to do this might be to map the equirectangular image onto a sphere and using a real-time API (eg: Opengl) view the result with a virtual camera located in the center of The equirectangular projection (also called the equidistant cylindrical projection or la carte parallélogrammatique projection), and which includes the special case of the plate carrée projection (also called the geographic projection, lat/lon projection, or plane chart), is a simple map projection attributed to Marinus of Tyre, who Ptolemy claims invented the projection about I have found multiple questions regarding fisheye → equirectangular conversion, in this and other forums. Contributions. In panoramic photography, it allows for the creation of complete 360-degree horizontal and 180-degree vertical views. 4. A great circle is the intersection between a plane and a sphere if pyEquirectRotate support equirectangular rotation with pure python codes. This stretching is reduced in the >Mercator projection by the natural logarithm scaling. h: Output equirectangular height. Write better code with AI Security. Elimination of Can be used via a CLI or directly in Python. linspace(90,-90, 6); X, Y = np. The x y. Added functionality like creating I am currently working on eeg signals, so here basically we have electrodes which are placed on head of a person and we get 3d coordinates of each electrodes so basically i am trying to find 2d coordinates from these 3d coordinates but with the help of equirectangular projection ( the same way how we project globe on a plane paper). 1 specification (plus some hacks to make it work). $\endgroup$ – Robin. This tutorial is part of the “Integrate Python with Excel” series, you can find the table of content here for easier navigation. The projection is neither equal area nor conformal. 😉 Where: xˉ is the sample mean. This involves calculating the dot products and then applying the projection formula. 6 (c++ is WIP). Basically it is quite obvious if you read about the equirectangular projection. Skip to content. [2] Significant changes have been made to improve the real-time performance of the code. The Haversine Formula, considering the Earth as a sphere, offers better accuracy than the Equirectangular method but still simplifies the Earth’s shape With an equirectangular projection, the mapping is direct and linear. 😎. Outline: Why we need map projections. add_subplot to signify the Some projections preserve distance from some standard point or line. Could you please advise where is equirectangular projection located exactly? – Valeria. Projector as of version 3. def convertCoords( azimuth, altitude ): # Assumptions: # - Both Using python to calculate radial angle, in clockwise/counterclockwise directions, Equirectangular projection The equirectangular projection (also called the equidistant cylindrical pro-jection, geographic projection, plate carré or carte parallelogrammatique projection or CPP) is a very simple map projection attributed to Marinus of Tyre, who Ptolemy claims invented the projection about 100 AD. The same CRS can often be referred to in many ways. GitHub page. Code Command line Python script that 1) takes logo file, 2) converts to equirectangular image, 3) transforms to desired size, and 4) overlays on-top of an equirectangular photo as a nadir. But when the projection plane is tilted, (py0 != panorama. This code supports (yaw, pitch, roll) rotation, described in this Wikipedia page. Cylindrical projections in general have an increased vertical stretching as one moves towards either of the poles. Mapping 3d coordinates to 2d coordinates using equirectangular projection. Only used by GPU rendering. dot(x, y) / np. The formula then can be modified as: y * np. Home Projects . Depending on the extent and the distortion property of the map, the application returns a list of appropriate map projections with additional projection parameters if necessary. tif gdal_rasterize -b 1 -b 2 -b 3 -burn 40 -burn 40 -burn 220 \ -at -l dst2 dst2. Equirec2Perspec is a python tool to split equirectangular panorama into normal perspective view. ; In Python, we can use popular library like SciPy and NumPy that make calculating confidence intervals using the t-distribution simple. --cpu: Use the CPU rendering implementation. This introductory text is modified from a tutorial on working with geospatial data using the library cartopy that was presented at the 2018 Scipy conference by Phileas Elson (lots of great things The description you mention states that the projection by a pin-hole camera (one that does not introduce lens distortion) is modeled by. linspace(-90, 90, 6); y = np. shp equirectangular-tmp. The wiki Projection Wizard is a web application that helps cartographers select an appropriate projection for their map. To go from Mercator to Equirectangular, you need to first (reverse) project Mercator (NE) to Lat/Long, and then (forward) project Lat/Long to Equirectangular (NE). An equirectangular image is always in G. I know (lat,lon) in left-top projection. however, I would like to implement 360 degree equirectangular image stitching. No need for other dependencies except for numpy and torch. We need to create our translation matrix by defining the location of the upper left hand corner. EDIT: As @VaidAbhishek commented, the above formula is for the scalar projection. , the equirectangular projection and cubemap projection, and their mutual conversion. Converting fisheye image to equirectangular image¶ The python version of the code is inspired by this repository. Given an input of 360 degree panorama. The other formula for Vector Projection of A on B is given as the product of A and B divided by the magnitude of B. def convertCoords( azimuth, altitude ): # Assumptions: # - Both values are in radians # - South is an azimuth of 0, negative to the left, range -pi to +pi # - Altitude range is -pi/2 to +pi/2, negative down x = 2880 + (azimuth * 2880 / math. Types of projections for different situations. Python. In other words, pixels along x directly correspond to longitude and pixels along y directly correspond to latitude. I know (lat,lon) in left-top and bottom-right positions. For example, one of the most commonly used CRS is the WGS84 latitude-longitude projection. Add a comment |. . Much slower and doesn't support linear Equirectangular projection is a map projection that represents a spherical image on a flat, rectangular surface. I have found py360convert, which allows convert from equirectangular to cubemap, from which it should be Python implementation of convertion between equirectangular, cubemap and perspective. ejizwj wnrvn uesf drww pxkm dohbxy osl kyqn ukdnf jsic