HI, i m begginer…
how to generate ndvi index … if I already have two images (NIR and RED), but I don’t know how to proceed.
thank you
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Oh, fun!
Let’s start with what camera and filter gave you those images.
micasense altum - 6 band (blue, green.red,nir,ir,thermal)
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Excellent. This can be accomplished in many ways. Are you looking to do this within ODM, or are you okay using other tools like QGIS?
in the qgis software I already managed, but I would like to use the ODM platform
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Saijin_Naib: I am looking at a drone that sensor has NIR, green, and red bands. The images are saved as 3 tiff images. Image1.tif is the NIR band, Image2.tif is the green band, and Image3.tif is the red band. Each each band is a tiff file. How do you make an orthomosaic using 3 tiff images for each photo site? Do the 3 original tiffs need to be combined into 1 tiff with 3 bands ( NIR, G, & R )?
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No, you should not need to merge them, if they are tagged properly, WebODM should read the tags from the images and group them accordingly.
Thank you.
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I have attempted to run the images as they are and WebODM messaged “Cannot process dataset”.
The images are labeled: “XACT0221.TIF, XACT0222.TIF, XACT0223.TIF, XACTO231.TIF, XACT0232.TIF, XACT0233.TIF, XACT0241.TIF, XACT0242.TIF, XACTO243.TIF, … XACTO371.TIF, XACT0372.TIF, and XACT0373.TIF”. The last digit is the band with 3 bands (1 Green, 2 Red, and 3 NIR). The image site is the first 3 digits starting with “0”.
What file structure is WebODM looking for when processing multispectral imagery?
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It is looking to associate the images with one another by the EXIF tags.
What sensor are you using?
XACTI CX-GB3000 is the camera. It produces a Red tiff, Green tiff, and an Near IR tiff. So there are 3 separate tiff images instead of a tiff image with 3 bands.
Camera Specs: fl=10mm, 2720 x 1815, Bit depth 16, f/4, exposure 1/2000 sec, Max aperture 2.97.
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Do the EXIF for each image call out the bandname properly?
Here is the EXIF data a green band tiff: Filename - XACT0221.TIF
ImageWidth - 2720
ImageLength - 1814
BitsPerSample -
Compression - 1 (None)
PhotometricInterpretation - 1
Make - XACTI
Model - CX-GB300
StripOffset - 196608
Orientation - Top left
SamplesPerPixel - 1
RowsPerStrip - 1814
StripByteCount - 9868160
XResolution - 72
YResolution - 72
PlanarConfiguration - 1
ResolutionUnit - Inch
Software - 1.08
DateTime - 2024:01:19 03:13:42
ExifOffset - 2384
ExposureTime - 1/2000 seconds
FNumber - 5.60
ExposureProgram - Shutter priority
ISOSpeedRatings - 400
DateTimeOriginal - 2024:01:19 03:13:42
DateTimeDigitized - 2024:01:19 03:13:42
ApertureValue - F 5.60
ExposureBiasValue - 0.00
MaxApertureValue - F 2.80
SubjectDistance - 3.91 m
FocalLength - 10.20 mm
ExifImageWidth - 2720
ExifImageHeight - 1814
FocalPlaneXResolution - 2083
FocalPlaneYResolution - 2083
FocalPlaneResolutionUnit - Centimeter
White Balance - Manual
FocalLengthIn35mmFilm - 28 mm
Serial Number - CXM001C00064
GPS information: -
GPSVersionID - 2.3.0.0
GPSLatitudeRef - N
GPSLatitude - 34 11 20.12532 (34.188924)
GPSLongitudeRef - W
GPSLongitude - 118 13 0.756839 (118.216877)
GPSAltitudeRef - Sea level
GPSAltitude - 438.49 m
GPSTimeStamp - 18 14 21.083
GPSDateStamp - 2024:01:18
Maker Note (Vendor): -
I do not see any mention of a color or band but, I am not sure what I am looking for. This is the first time I have used NIR imagery.
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What is the EXIF field that designates the image’s band?
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do you have a NIR band image that I can look over the EXIF data. I have run the 3 separate images in webODM and made 3 mosaics (Red, Green, and NIR). They overlay in Qgis but not able to generate a nice psuedo color image with them.
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There should be a Band field in the EXIF.
exiftool IMG_180822_135805_0467_NIR.TIF
ExifTool Version Number : 12.87
File Name : IMG_180822_135805_0467_NIR.TIF
Directory : .
File Size : 2.5 MB
File Modification Date/Time : 2019:11:22 09:00:34-05:00
File Access Date/Time : 2024:10:17 01:16:48-04:00
File Inode Change Date/Time : 2024:10:17 01:16:27-04:00
File Permissions : -rwxr-xr-x
File Type : TIFF
File Type Extension : tif
MIME Type : image/tiff
Exif Byte Order : Little-endian (Intel, II)
Image Width : 1280
Image Height : 960
Bits Per Sample : 16
Compression : Uncompressed
Photometric Interpretation : BlackIsZero
Image Description : 790 nm
Make : Parrot
Camera Model Name : Sequoia
Strip Offsets : 8
Orientation : Rotate 180
Samples Per Pixel : 1
Strip Byte Counts : 2457600
Min Sample Value : 0
Planar Configuration : Chunky
Software : v1.5.0
Modify Date : 2018:08:22 13:58:05
Rig Name : Sequoia
Rig Camera Index : 3
Yaw : -57.306736
Pitch : 28.387545
Roll : 1.071882
Band Gain : 1.000000
Sensor Temperature : 58.260864
Line Readout Time : 23076
Rig Relatives : -0.45345926367459,-0.299246289583098,0.178292827318906
Principal Point : 2.371143,1.836839
Model Type : fisheye
Fisheye Affine Symmetric : 1
Fisheye Affine Matrix : 1671.093926051,0,0,1671.093926051
Fisheye Polynomial : 0,1,0.017881608,-0.16164181
GPSXY Accuracy : 0.548715
GPSZ Accuracy : 0.953000
Flight UUID : 44F86636D1233801E519B2EC29A1F4BD
Capture UUID : 6FB9933E3BB20D92837D9CE142AF4E94
Sunshine Serial Number : PI040379BB7K008492
Irradiance Calibration Measurement: 0,600,41,19,1,600,1004,503,2,600,17140,8387,3,600,65535,65535
Calibration Measurement : 1,0.00427350427350427,514
Calibration Picture : 0
Irradiance Calibration Measurement Golden: 0,600,38,19.,1,600,947,486.,2,600,15769,7882.,3,600,65535,65535
Irradiance Sensitivities Golden : 614.221848,312.698984
Irradiance Unit Scale : 1.7873713395012918
Sensor Model : 311992417.58091587,4102.139974586678,3223.8629870706945.
Band Name : NIR
Central Wavelength : 790.000000
Wavelength FWHM : 40.000000
Black Current : 76.000000
Vignetting Polynomial 2D Name : 0,0,1,0,2,0,3,0,4,0,0,1,0,2,0,3,0,4,1,1,1,2,1,3,2,1,2,2,3,1
Vignetting Polynomial 2D : 0.7588606611753627,1.0472290605575059,-2.1363409203035819,2.1894221485527647,-1.0565150613962060,0.4239585602722019,-0.6349717485239196,0.3714456229766867,-0.1788391105065560,-1.0573846227800299,1.0258238253111314,-0.0201640346723835,1.1169986400789595,-1.0472817972122375,-0.0261714586792751
Invalid Pixel : 152,13
Irradiance List : .OMniNQAAAAB2BbkCAQBkAJEeGUNe7J3BOC+EwGnT5TUAAAAAhgXCAgEAZABtHhlD6haewd0ehMCM5+g1AAAAAGwFtQIBAGQARx4ZQwFCnsFMDoTA+v3rNQAAAAB0BbkCAQBkACEeGUM3bZ7Brf2DwG0N7zUAAAAAaQW0AgEAZAD8HRlDDZiewTXtg8BzFPI1AAAAAG8FtgIBAGQA2B0ZQ2zCnsHr3IPAkCL1NQAAAABgBa8CAQBkALMdGUMt7Z7BecyDwEsv+DUAAAAAUgWnAgEAZAAQTBlDegCewenVj8A=.
Exposure Time : 1/1444
F Number : 2.2
Spectral Sensitivity : 790 nm
ISO : 100
Date/Time Original : 2018:08:22 13:58:05
Create Date : 1970:01:01 00:15:05
Shutter Speed Value : 1/1444
Aperture Value : 2.2
Max Aperture Value : 2.2
Focal Length : 4.0 mm
Image Number : 467
Sub Sec Time : 683541
Sub Sec Time Original : 683541
Sub Sec Time Digitized : 615954
Exif Image Width : 1280
Exif Image Height : 960
Focal Plane X Resolution : 266.6666559
Focal Plane Y Resolution : 266.6666559
Focal Plane Resolution Unit : mm
Exposure Mode : Auto
Focal Length In 35mm Format : 30 mm
Image Unique ID : 171E0500F46345D825CC563842F8A3DB
Serial Number : PI040378AE7K007272
GPS Version ID : 2.2.0.0
GPS Latitude Ref : North
GPS Longitude Ref : East
GPS Altitude Ref : Above Sea Level
GPS Time Stamp : 13:58:05.663
GPS Status : Measurement Active
GPS Speed Ref : km/h
GPS Speed : 30.37535149
GPS Map Datum : WGS-84
GPS Date Stamp : 2018:08:22
Black Level Repeat Dim : 2 2
Black Level : 5536 5556 5577 5581
Camera Serial Number : PI040378AE7K007272
Original Raw File Name : IMG_180822_135805_0467_NIR.TIF
Aperture : 2.2
Image Size : 1280x960
Megapixels : 1.2
Scale Factor To 35 mm Equivalent: 7.5
Shutter Speed : 1/1444
Create Date : 1970:01:01 00:15:05.615954
Date/Time Original : 2018:08:22 13:58:05.683541
Modify Date : 2018:08:22 13:58:05.683541
GPS Altitude : 293.1 m Above Sea Level
GPS Date/Time : 2018:08:22 13:58:05.663000292Z
GPS Latitude : 50 deg 59' 7.57" N
GPS Longitude : 21 deg 25' 28.88" E
Circle Of Confusion : 0.004 mm
Field Of View : 61.9 deg
Focal Length : 4.0 mm (35 mm equivalent: 30.0 mm)
GPS Position : 50 deg 59' 7.57" N, 21 deg 25' 28.88" E
Hyperfocal Distance : 1.81 m
Light Value : 12.8
From the picahoo_nir_1 dataset here:
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Thank you so much. I have contacted the supplier of the imagery and they have submitted the issue to their engineers. Hopefully they will add this information to the EXIF data to their images.
I went to the GetHub site but do not know how to download the imagery. Is this possible / if so how?
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You click on the dataset name in the table.
Here is the link:
Thanks for bringing it to their attention!
Thank you for your help.
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