Equirectangular projection formula calculator 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. 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. Examples of projections that preserve distances along meridians (but not parallels): Equirectangular / Plate Carree. 6. @ashleedawg - The Haversine formula is a particular method for estimating distance between two points assuming Earth is a sphere. 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. Regarding Python, the following modules are used: cv2 : CPU-Only OpenCV for Python. gdal_rasterize -b 1 -b 2 -b 3 -burn 40 -burn 40 -burn 220 \ -l dst1 dst1. 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. 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. How do I project this now on a 1366x768px browser screen? Equations and code behind conversion between equirectangular images and cubemaps. [2] Significant changes have been made to improve the real-time performance of the code. Panorama. This tutorial is part of the “Integrate Python with Excel” series, you can find the table of content here for easier navigation. Home Projects . Compatible with cuda tensors for faster processing. 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. 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. GLSL. I have a 13312 px width and 6656 pixel height Panorama picture. Python implementation of convertion between equirectangular, cubemap and perspective. 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. 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. Only used by GPU rendering. 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. 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. R_u = f*tan(theta) and the projection by common fisheye lens cameras (that is, distorted) is modeled by. 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. EDIT: As @VaidAbhishek commented, the above formula is for the scalar projection. 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. Basically this is the Pythagorean theorem. 10 from the OpenGL 4. Code With an equirectangular projection, the mapping is direct and linear. Looking back at our definitions of our coordinates X and Y we can see that they are defined with x = np. Rasterization is almost the same as in the previous case. 1. however, I would like to implement 360 degree equirectangular image stitching. ; t is the critical value from the t-distribution based on the desired confidence level and degrees of freedom (df=n−1). Equirectangular Projections. The following maps a cylindrical projection onto the 6 faces of a cube map. 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. In this cube I do rotations around it's origin and create images using glReadPixels. But when the projection plane is tilted, (py0 != panorama. I wrote the code to be numpy-friendly. ; s is the sample standard deviation. I saw this formula on Wikipedia and it works perfectly for my use case. 1 specification (plus some hacks to make it work). 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. Commented Apr 3, 2014 at 15:20. Does someone know a python solution to get the Azimuthal projection from an Equirectangular o from an Vector Projection Formula. 6 (c++ is WIP). 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. --nearest: Use nearest sampling for stretching that will occur due to change of aspect ratio. linspace(-90, 90, 6); y = np. In other words, pixels along x directly correspond to longitude and pixels along y directly correspond to latitude. 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. --to_mercator: Convert the image to the Mercator projection. Contributions. 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. w: Output equirectangular width. I know (lat,lon) in left-top projection. The wiki Projection Wizard is a web application that helps cartographers select an appropriate projection for their map. org. Looking at each pixel in our UV texture, we represent its position along the u-axis as an azimuth angle on the unit sphere. I invite you to look at the wikipedia page on Haversine formula if you want to explore other methods. [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. 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). 2024. I am trying to transform an equirectangular projection to an azimuthal projection with python. It's the texture for an attitude indicator, b. You can rotate equirectangular images by rotating the surface of a sphere. Converting fisheye image to equirectangular image¶ The python version of the code is inspired by this repository. 8. . 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. See also sphere2cube . Outline: Why we need map projections. An equirectangular image is always in G. 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. 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. add_subplot to signify the Some projections preserve distance from some standard point or line. import os import cv2 import Equirec2Perspec as E2P if __name__ == '__main__': equ = E2P. D. 3 Map Projections¶. Equirectangular Projection is the representation of a spherical surface by uniformly sampling it in longitudinal and latitudinal angles. I have found py360convert, which allows convert from equirectangular to cubemap, from which it should be easier to obtain an azimuthal projection. I have found multiple questions regarding fisheye → equirectangular conversion, in this and other forums. (equirect2cube, cube2equirect, equirect2perspec) - sunset1995/py360convert (equirect2cube, cube2equirect, equirect2perspec) - sunset1995/py360convert Converts between the equirectangular and mercator projections. The formula then can be modified as: y * np. Skip to content. Haversine is common but there is not a "standard" formula. Indeed, the poles themselves can't be represented (except at infinity). A blazing fast, shader based image projection converter. The sampling grid is rectangular, in For more on equirectangular projection, both Wikipedia and Wolfram Mathworld are quite useful. A 360 camera was used to generate * the two input fisheye images. The Projection Wizard is based on John P. shp equirectangular-tmp. This involves calculating the dot products and then applying the projection formula. Elimination of The same thing applies to the azimuthal projection: You can go from azimuthal coordinates -> equirectangular -> mercator and sample the image. linspace(90,-90, 6); X, Y = np. 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. To obtain vector projection multiply scalar projection by a unit vector in the direction of the vector onto which the first vector is projected. ; In Python, we can use popular library like SciPy and NumPy that make calculating confidence intervals using the t-distribution simple. It's a equirectangular projection of a room and have a 2:1 ratio. Each camera has been calibrated independently and the extrinsics between the two * cameras is assume to be known. 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. It’s all about defining the correct transformation maps for OpenCV. I am attempting to calculate the bearing between two lat/long. Its aspect Python implementation of convertion between equirectangular, cubemap and perspective. Add a comment |. Equirec2Perspec is a python tool to split equirectangular panorama into normal perspective view. 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. Parameters: cubemap: Numpy array or list/dict of numpy array (depend on cube_format). height/2), lines are warped. The x y. The projection is neither equal area nor conformal. Examples of Vector Projection: Projection of One Vector onto Another: Use the formula to find the projection of vector A onto vector B. 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. 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. This stretching is reduced in the >Mercator projection by the natural logarithm scaling. 360 (MAX only) files into single frames with correct metadata. 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). Python. Sign in Product GitHub Copilot. Converts GoPro . A great circle is the intersection between a plane and a sphere if pyEquirectRotate support equirectangular rotation with pure python codes. Perpective. We again got two new shapefiles for data in equirectangular projection. 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. ‑‑to_equirectangular: Convert the image to the Equirectangular projection. Cylindrical projections in general have an increased vertical stretching as one moves towards either of the poles. by Marinus of Tyre. ) We pass an instance of the projection class to the projection keyword argument of Figure. No need for other dependencies except for numpy and torch. Could you please advise where is equirectangular projection located exactly? – Valeria. The example here will eventually lead to a more complex model where we build a mortgage calculator in Python. 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. This code supports (yaw, pitch, roll) rotation, described in this Wikipedia page. 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. 🌏. 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. 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. I study a lot of resource on the internet. 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. numpy : Tools for scientific computation, used for its fast n-dimensional arrays. I know this is a equirectangular projection. 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. 😉 Where: xˉ is the sample mean. For reference codes of the most commonly used projections, see spatialreference. To get in touch with me you can message me on LinkedIn, Twitter, or YouTube. 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. 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. h: Output equirectangular height. (equirect2cube, cube2equirect, equirect2perspec) Fast and Simple Equirectangular Rotating python code 😎. Converts between the equirectangular and mercator projections. Find and fix This utility extracts a perspective projection from a set of 6 cube maps images. I've seen various ways of doing this and a few questions on Example code for equirectangular to perspective conversion fisheyeUtils. 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. sys : Access to system variables and functions from the interpreter (usually comes with Python) PIL : Python Imaging Library, used for image file manipulation. $\endgroup$ – Robin. The same CRS can often be referred to in many ways. But I have no idea how to performance this projection by OpenCV. 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. We need to create our translation matrix by defining the location of the upper left hand corner. Goal: Introduce the concepts of projecting 3D spherical geography onto a 2D plane. mp4 (any GoPro) or . 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). I use following formular to calculate the xPosition: var xPosition = ( panorama. Multiply the resulting scalar by vector B to obtain the projection of A onto B. - Xyene/sphere2cube Where: xˉ is the sample mean. tif gdal_rasterize -b 1 -b 2 -b 3 -burn 40 -burn 40 -burn 220 \ -at -l dst2 dst2. Basically it is quite obvious if you read about the equirectangular projection. In this tutorial, we are going to learn how to build a simple cashflow projection model in Python. 10. --cpu: Use the CPU rendering implementation. 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. How does one A blazing fast, shader based image projection converter. dot(x, y) / np. 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). - Xyene/cube2sphere. 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. 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. Check it out on on GitHub! We will start with the very straightforward Plate Carrée (also known as Equirectangular or Equidistant Cylindrical. Usage (1) Mercator and Equirectangular are two different map projections. , the equirectangular projection and cubemap projection, and their mutual conversion. 😎. 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. 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. 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. For example, one of the most commonly used CRS is the WGS84 latitude-longitude projection. 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. Both OpenCV code or Mathematica formula a The equirectangular projection was used in map creation since it was invented around 100 A. (2) Mercator and Equirectangular formula each has two forms - one for ellipsoid, and one for sphere. The resulting equirectangular projection is as follows. I know (lat,lon) in left-top and bottom-right positions. 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. Probably taking a look at The apsect ratio is calculated as follows: ar = screen width / screen height. Or you can find a formula to go directly from azimuthal -> mercator. 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. GitHub page. Mapping 3d coordinates to 2d coordinates using equirectangular projection. width / 360 ) * azimuth Azimuth = Phi = Heading = Angle to the left or right. Elimination of Can be used via a CLI or directly in Python. 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. 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). 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. 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. Map projection converter. Given an input of 360 degree panorama. dot(y, y) for the vector projection of x onto y. In panoramic photography, it allows for the creation of complete 360-degree horizontal and 180-degree vertical views. For a reason I can’t remember, I started wondering what a great circle would look like in an equirectangular projection. Projector as of version 3. Split panorama into perspective view with given parameters. I have a piece of a map in equirectangular projection. Navigation Menu Toggle navigation. 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. Types of projections for different situations. Verify its presence, or install it using `pip install tk`. Supports 360 Developed using Python>=3. 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. Write better code with AI Security. Much slower and doesn't support linear Equirectangular projection is a map projection that represents a spherical image on a flat, rectangular surface. 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. 4. 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. See Mathworld's page for more detailed information on the mathematics of this projection. With that background information out of the way, let's move straight into our first application of the spherical coordinate system: the Equirectangular Projection. Usage. All answers proposed/explained how to implement it from scratch, mostly relying on Paul Bourke’s tutorial. e. 0, along with alternative names and An equirectangular projection of the Earth; the standard parallel is the equator. 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. 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. ; n is the sample size. Can be used via a CLI or directly in Python. From the formula In this section, we introduce the two common projections for the spherical image, i. In this cube I do rotations around it's origin and create images using glReadPixels. gctvj imbe zhthcv jgdnlf motn joc qodgns isntldy qfz auitqc