Questions tagged [orthophoto]

An aerial photograph geometrically corrected and adjusted for topographic relief, lens distortion, and camera tilt - such that the scale is uniform.

34 questions with no upvoted or accepted answers
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84 views

Rotating orthophoto based on polygon boundary (rotated pixel)?

When I clip an orthophoto using a vector polygon, the resulting pixels orientation is north-up like as shown in the graphic below. I used Global Mapper, ERDAS, Arcmap "Clip" "Extract by Mask", "...
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1answer
121 views

Measure building lean in ArcMap?

I was wondering if anyone is aware of any tools that are available to measure building lean in ortho images from within ArcMap. I am aware of calculations and processes that can be used to measure and ...
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187 views

Orthophoto land use classification in QGIS

I am using a CIR orthophoto and tried to make a land use classification with the use of Semi-Automatic Classification Plugin in QGIS. I work in QGIS 3.2 but I get errors that my ROI are too small (...
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22 views

Scale bars moving after update cause measurement issues

I'm trying to create orthomosaics with accurate measurements of rocks in a stream bed. All the photos were taken from a fixed height and scale bars were added by knowing the dimensions of GCP's along ...
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66 views

Trying to deal with pure whites, and transparency of orthomosaic in MapInfo

I'm hoping to deal with this using the raster calculator in QGIS. But, here's my issue (and I'm a pretty novice GIS user); when you bring a raster image into MI, it turns all the null ("no data") ...
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68 views

Orthophoto processed with Photoscan distorted in QGis

I processed an orthophotomosaic via Photoscan using geotagged images in EPSG 4326 and it is displayed correctly in Photoscan and GoogleEarth. When I put it in QGis it is distorted. The coordinate ...
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226 views

DroneDeploy generated Ortho shows skewed in QGIS (projections OK?)

I've recently bought a drone and have been having a lot of fun enhancing maps with very detailed orthomosaics. The images place correctly once loaded in QGis, absolute positioning is good enough for ...
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121 views

Using Orthophotos - not multispectral - to generate Object-oriented image classification vectors?

I'm using QGIS version 2.14.3-Essen on a Macbook pro. I'm sort of new to this and feeling my way through this. I have high-resolution Orthophotos officially sourced from local country in Sub-saharan ...
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276 views

extract roads, railways and canals out of old orthophoto

how is it possible to extract the roads, canals and or railways out of this image (black-white)? Or how is possible to create lines at the edges of the roads, canals and or railways?
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46 views

Geometric quality of orthophotos

I have a lot of historical orthophotos, like the year 1950 of a region I have also of the same region the orthophotos of more recent years such as 2012 The question is how to compare and quantifying ...
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389 views

Georeferencing declassified CORONA images of coastlines?

I'm trying to georeference declassified CORONA images of coastlines in order to asses coastline changes and human impact. In most case, georeferencing is easy, but since images of coastlines can only ...
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343 views

3D visualization of terrain data and orthophoto using GRASS NVIZ via QGIS

How can I make 3D visualization of terrain data and orthophoto using GRASS NVIZ via QGIS? I am quite new with GRASS. I have only managed to get a 3D view of the terrain so far.
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93 views

Using ERDAS Imagine 2020 orthophotos

I am dealing with how to figure it out how to export an orthomosaic from my Agisoft Metashape because when I did the merge chunks there. When you merge there, it doesn't provide what I need because of ...
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33 views

Combining orthophoto and DEM to export xyz-CSV

I have a georeferenced orthophoto and a DEM as tiff-file. For my further workflow I want to export x,y,z (x,y from the orthophoto and z from the DEM). I already managed to create a point layer and ...
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45 views

Co-registering multiple temporal orthomosaics?

I have multiple (19) orthomosaics of the same approximate region taken regularly over the course of a couple months with a UAV. Some, but not all, include ground control points we placed in the scene....
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1answer
601 views

How to import orthomosiac from metashape into QGIS and preserve ortho appearance?

The beautiful image that you see is an orthomosaic [apparently this is not a yet a tag on this forum] generated in Agisoft Metashape [also not a yet a tag] with imagery captured with drone mounted ...
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65 views

Rotating ortho-satellite imagery so that square polygon perpendicular to the viewer

I'm trying to figure out how to rotate this satellite geotiff so that the rooftop polygon would appear as square as possible to the viewer rather than a diamond shape. See example below. How to ...
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237 views

Orthorectification with R

How can I orthorectify an oblique image of a flat landscape when I know the conditions of the photo (coords, height, direction, lens, etc)? I would like to perform this kind of stuff from GRASS ...
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31 views

Where can I find decent resolution (5m ish) night time orthophotography/satellite imagery data for Ireland?

Anything I've found so far has been incredibly granular. I need a resolution which is fine enough to see general lighting footprints for motorway junctions.
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38 views

Light normalization of Orthophotos to increase comparability

I would like to work with the RGB-values of different orthophotos. Now I noticed that the light conditions are not the same in the different orthophotos. I was wondering if there is a sound way to ...
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125 views

Method in QGIS to classify veg from HiRes geotiffs created in Pix4D?

I have 10 2D geoTIFF orthophotos (~2GB each, ~3km2 each, all 4.2cm/pixel) that I generated from Vis RGB 12MP images in Pix4D for a desert vegetation survey over 30km2 for a development. I need to ...
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460 views

Storing non-orthorectified images in GeoTIFF

I'm reading GeoTIFF and GDAL documentations and I'm trying to understand what type of transformations are supported. GeoTIFF documentation says you can use ModelTransformationTag to define a ...
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134 views

Aerial mosaic of thermography

I have a large set of aerial images (thermography) some of them are very tilted due to the airplane turning. I want to merge all the images into a unique orthorectified image. I have not the GPS ...
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72 views

Automatically applying a local ortho projection using the center of the raster layer extent

I would like to take a raster image read the layer extents, extract the center point and then apply a custom local ortho projection with the origin set to the extracted center point. Can anyone ...
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17 views

gdalwarp on County-wide mosaic or COG takes forever or seems to hang

I am creating Cloud Optimized GeoTIFFs using gdal from a folder of TIFF files in GDAL for an entire county. After creating a mosaic of these files (in EPSG:6551) using gdalbuildvrt I can create a COG ...
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11 views

ArcGIS Pro 3d scene production

I am trying to do a simple 3D scene with orthophoto raster mosaic and DEM. The problem is that not all orthophotos render (are visible). Only approximately 50%. If I have 9 orthophotos in a mosaic, ...
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17 views

Area measurement validation: ellipsoid vs geoid

I try to validate area measurements on orthomosaics using objects of known size on the ground. I'm working on centimeter level measurements. As far as i understand an orthomosaic in WGS 84 is ...
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23 views

Adding ortophoto to map through hyperlink in ArcMap

I would like to add layers (more specifically Orthophotos) through the hyperlink function in ArcMap 10.3. With hyperlinks it is possible to add script (VBscript), documents and URL. If I add the ...
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40 views

Calculating exterior and interior orientation of any drone without camera calibration

I have a drone, how can I find the projection matrix without calibration? Since the drone has a GPS, I know some angles and the distance between the two photos in meters. I also know the formula of ...
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136 views

Automatically georeference non-intersecting UAS photos based on contained EXIF metadata

I need to know how to automatically create georeferenced rasters from multiple non-intersecting photos taken by UAS DJI Phantom 4 Pro. All EXIF metadata is present in every photo - coordinates, ...
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67 views

Splitting GeoTIFFs

I have three different GeoTIFF orthophotos I am trying to tile (the editing program I use can't accept the GeoTIFFs as is), and I would like to retain the geographical information. Can someone offer ...
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48 views

How to retrieve GIS data in Multiple Orthophoto at point level

I have been using a python script that can read Data from Orthophoto(*.tiff) of size 300Mb-2Gb. But this is taking 32s per request of lat-long, which is not ok. I have different Orthophotos with ...
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50 views

Grass Gis: What is the meaning of a TARGET LOCATION?

I am attempting to follow a guide on creating ortho-photos in Grass GIS, available here: https://grassbook.org/extra/sample-chapter/ The chapter suggests that a separate cartesian LOCATION should be ...
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1answer
64 views

Converting a drone orthophoto saved as KMZ to TIFF in QGIS

Dragging a drone-obtained orthomosaic image saved as a KMZ file (167mb) into QGIS results in the image being very poor resolution. But when KMZ file is loaded into Google Earth, it's very high ...