Questions tagged [digital-image-processing]

The field of raster image processing

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67 views

i.spectral tool error

system description: Windows7 32 bıt OS, Grass GIS 7.0.0 Gnuplot 5.0 Solution attempt 01: On the basis of following thread, commented out said path check lines from i.spectral.py script: https://...
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1answer
610 views

How to aggregate/resample a higher resolution image to coarser resolution using defined threshold?

I've got a 30 m classification image and i'd like to convert it to 500 m resolution using a user-defined threshold value. Basically what i'd like to accomplish is similar to using the Resample tool ...
6
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1answer
2k views

Random Forest land cover classification in ArcMap?

I am an undergraduate student working with a very large data set (to me), and who has NO experience with R, but is fairly comfortable with ArcMap. I have about 60GB of 8band 1m satellite imagery of ...
4
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1answer
96 views

Classifying areas in scanned maps (not by colors but by pattern)

I have old land-use maps in a scanned format. I am trying to obtain proper land-use maps from it, similar to what is decribed here: Comparing areas in scanned historical land use maps using QGIS?. The ...
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2answers
621 views

Devide heatmap into meaningful clusters

I created a heatmap containing population density data. Now I want to figure out the hotspots of this heat map. In other words: Where are the biggest population densities in my map? My first thought: ...
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0answers
49 views

How to digitize infrared slides for use in GIS?

I have an aerial infrared slide with the following dimensions 20cm x 30cm. It was captured with an infrared camera from a height of around 3000m a few years back and now my environmental agency would ...
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0answers
71 views

How to extact very narrow water linear features from GeoEye-1 image

I need to extract beaver channels from a GeoEye image (attached image). What is the best approach to automatically delineate such very narrow and not very sharp water features?
2
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1answer
373 views

How to suppress noises of this edge-detected image? [closed]

I've recently developed a new approach to detecting image edges. Everything seems to be normal except the noises! As you can see in the following image, there are many noises I'm not able to handle ...
3
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1answer
2k views

supervised classification

I am having a problem in creating new signatures in Signature Editor in ERDAS 2014. Whenever I click on the icon (i.e., after selecting the aoi), it shows an error which says "unable to open ...
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1answer
5k views

SAR - Using the Intensity or the Amplitude for the classification

In a Sentinel-1 Level 1 Ground Range Detected SAR data product, Intensity = Amplitude * Amplitude. Should the intensity image or the amplitude image be used for radiometric calibration when using ...
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3answers
1k views

How to use rsgislib python binds in windows environment

I am right now would like to use rsgislib to create a simplify remote sensing image processing application based on python. However I have no idea about how to use rsgislib in windows. Perhaps ...
2
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1answer
262 views

How to separate out bands from hyperspectral data using R

I'm having one hyperspctral data with 426 bands, with dim 250*250*426. I want to seperate each bands. I tried like this img <- stack("name.tif") rr <- array(, dim= c(250,250,426)) for(i in 1:...
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1answer
869 views

Otsu thresholding and classic image processing algorithms on radiometrically calibrated Sentinel-1 SAR images

Is it possible to apply the Otsu thresholding (or any other image processing algorithm dedicated to image digital values in the interval [0, 255]) to a Radiometrically calibrated Sentinel-1 SAR ...
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0answers
1k views

Histogram matching of two NDVI images

I have two Landsat 5 NDVI images (Surface Reflectance products) from the same period of the year (only a few days apart), but one is from the 1980s and one from the 2000s. I am trying to do a change ...
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1answer
665 views

Calculate NDVI with converted canon sx260 hs

I have converted my canon sx260 hs so it can capture NIR part of specter. Can anyone tell me how can i calculate NDVI now? My guess is that on the blue channel is now NIR value and Green channel=(...
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2answers
1k views

Mosaic Imagery using GDAL Edited

I have a couple of large sets of imagery I need to mosaic using GDAL. The sets are currently in tiff format with 18 tiles totaling about 20gb in size. I have attempted to mosaic using both the ...
2
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1answer
1k views

Calculating NDWI in Erdas IMAGINE 2014

I'm using MOD09GQ product of MODIS to calculate vegetation indices in Erdas 2014, and I was able to extract NDVI using Erdas Model Builder. What is the formula I should use in model builder for ...
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1answer
115 views

Conversion of multispectral image to grey scale

I have a composite with four bands NIR, Red, Green and Blue. I would like help on which weight values to use when converting it to a single band which will then be used to classify vegetation. I am ...
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1answer
126 views

Is there any comprehensive book or online instruction on image segmentation techniques? [closed]

I'm looking for a source to learn theoretical basis of image segmentation techniques thoroughly. The desirable book, or other kinds of source you may know, should cover the techniques that are more ...
3
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1answer
288 views

Determining the best month for discriminating between different vegetation types?

I ordered and downloaded several (Surface Reflectance) Landsat 5-8 images from USGS Earth Explorer with the purpose of choosing a few of them to calculate some Vegetation Indices for each (NDVI, SAVI, ...
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2answers
2k views

Tasseled Cap Transformation coefficient and Bias Value

I want to perform Tasseled Cap transformation of Landsat 5,7 and Landsat 8 data manually in ArcGIS. Please let me know where from I can get the coefficient values and Bias values for the following ...
0
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2answers
465 views

Classification of digital orthophoto

I have digital orthophotographs from 2013 that I'm attempting to classify in an effort to extract all the cultivated/pasture land from. I'm using the "Reclassify by Ascii File" tool for this ...
0
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1answer
933 views

Divide into grid and Mosaic using google earth?

Is it possible to download 1:2000 scale of a town using google earth image? If divide the whole area into grid and mosaic them is an option, how it is done using google earth? I tried using grid. But ...
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0answers
97 views

Important to perform atmospheric correction when attempting to identify coral reefs?

I want to identify coral reefs using multi-temporal Landsat data and Lyzenga's Transformation method. In relation to pre-processing the image, should atmospheric correction be done or not? If not, ...
2
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1answer
2k views

How do I convince gdal2tiles to output pngs with transparency?

I have a tiff that was created with Pix4dmapper. This tiff has coordinates embedded (as seen in the logs below) (I think that makes it a geotiff?) as well as a tfw file associated with it. Opening ...
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0answers
457 views

How to rectify a georeferenced Google Earth image and corresponding layer

I am still a newbie to georeferencing and ArcGIS. I imported an image with place markers from Google Earth. Then I opened up the image in ArcGIS Desktop 10.3.1. I then georeferenced the control ...
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0answers
534 views

Remote sensing Classification and texture analysis compared with QGIS zonal statistics

I am Using Geomatica to analyse suburban spectral signature in Las Vegas. Ran a texture analysis on all band images. Combined texture bands with original image bands to run an unsupervised ISODATA ...
3
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2answers
2k views

Raster image thresholding using python

Can someone guide me for applying thresholding technique to input raster image using Python. I intend to extract impervious surfaces from a high resolution raster such as roads, sideways and ...
8
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2answers
15k views

image segmentation of RGB image by K means clustering in python

I want to segment RGB images for land cover using k means clustering in such a fashion that the different regions of the image are marked by different colors and if possible boundaries are created ...
2
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1answer
390 views

How to remove compression from jpeg2000 NAIP imagery?

I downloaded a 4-band 1m spatial resolution NAIP image from Earth Explorer. The default image format is jpeg2000. You can see the trees in the attached image appear grainy, more so than what you ...
4
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1answer
348 views

Which preprocessing comes first for pansharpened imagery- atmospheric correction or orthorectification?

For pansharpened imagery, what preprocessing method to do first- is it atmospheric correction or orthorectification? From my readings, it seems the former but the rational polynomial coefficients or ...
1
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1answer
158 views

comparison of atmospheric correction methods

I have noticed that dos methods for atmospheric corrections are in the section of radiometric correction i.*.toar on GRASS GIS. Does that means that dark object subtraction (DOS) is a method for doing ...
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1answer
121 views

How to convert GOES-R (15) IR image from gray-scale to brightness temprature

How do I convert satellite IR images taken by GOES-R (15) from gray-scale to brightness temperature? We can download the IR satellite images, and read its RGBA values. But how can we convert this RGBA ...
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1answer
2k views

Removing Shadows from Aerial Imagery in ArcGIS

I am creating an automatic change detection tool in Python for ArcGIS 10.2 using aerial imagery. The tool works but it also detects shadow change. I have been able to create a classified raster of ...
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0answers
77 views

Sophisticated generation and calculation of Vector entities from Raster Data?

The first image below is shown a raster wish represents the altitude value. I created this raster by applying this process, bu using this process we can manually select an upper and lower area (so 2 ...
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1answer
462 views

How to separate details by color from raster?

How to separate details by color from raster? Is it possible in ArcGIS or any other software? I have tried Spatial Analyst. I want to use RGB .tiff image which is scanned map. It consists of all the ...
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2answers
1k views

Error in downloading MODIS image using R script

I am trying to download "MOD13A3" MODIS image using R script (http://r-gis.net/?q=ModisDownload) but each time it's ending in error. How to make it work ? =============================================...
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0answers
126 views

How to fit Google Earth satellite image to UK OS 50 DEM

I have extracted a DEM tile from the UK Ordnance Survey's free OS Terrain 50 dataset The tile contains spot heights for a grid comprising 51 nodes (West to East) by 51 nodes (North to South) with ...
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1answer
529 views

IR/R could not detect when using landsat 8 in ERDAS 2014 Is there a alternative way around?

I'm using ERDAS 2014 and I upgraded from ERDAS 2013. I am doing a lot of band indices for various kinds of such as clay, ferrous, Mineral composite and so on.. from landsat 8. Using the indices in ...
3
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2answers
3k views

How to perform an accuracy assessment in eCognition?

How to do accuracy assessment of classified images in ecognition? I have done the image segmentation for Worldview-2 image. Then, I have processed for classification for class names (e.g road,...
2
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1answer
1k views

How to remove band from stack in ERDAS 2013?

I have a Landsat 8 scene where I have stacked 11 bands. I need to remove one band from the stacked layer. Is there a toolbox in ERDAS 2013 that allows me to take out a band? I am aware that ENVI 5....
1
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1answer
148 views

Iterative Mean of Means Infinite Loop for calculating H-t Index

I'm trying to create a function that will calculate an Ht-Index for Quantifying the Fractal or Scaling Structure of Geographic Features (but am new to R) which basically just finds nested means of ...
2
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1answer
120 views

How to create an image of maximum pixel values from an input layer-stack image in ERDAS Imagine?

I have 12 MODIS images (one of each month). I want to create a single image having maximum annual pixel values for each pixel. I did layer stacking operation in Erdas Imagine 13, but how to extract ...
4
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3answers
301 views

Estimating vegetation composition from digital images

I am running a Master's project researching Greater prairie-chicken nest and brood survival. Some of my intended covariates include local vegetation measures using digital imagery. I would like to use ...
0
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1answer
276 views

Cut a hole into a geotiff

I have two hillshading geotifs that I created using gdaldem hillshade. One covers a huge area with an OK resolution and the other has a much higher resolution for a smaller part within the huge area. ...
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0answers
54 views

PMI and PMW images

i recently archieved .pmi and pmw images which converted from tiff. So now i can not open, please help me to open or convert this filetype to other aerial imagery formats.
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0answers
43 views

What are the advanced fusion techniques for fusing 3 band multispectral and 242 band hyperion hyperspectral dataset?

I have used some of the image sharpening techniques such as Wavelet, Gram-schmidt, Principal component, Brovey. Other than this what are the new and advanced fusion techniques and in which software it ...
2
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1answer
3k views

How to Read&Write .tiff images in java using GDAL library

I searched many sites to learn about this but I didn't find anything. I need step by step process for reading .tiff monochromatic image in java using Gdal library.
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1answer
595 views

Verifying landsat reflectance values? [closed]

I am still beginner in Remote Sensing. I have asked a GRASS programmer to prepare for me Landsat reflectance values from raw DN values (1 scene per year from 1987 to 2013). I have proposed him (...
6
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2answers
2k views

How to create a mosaic in QGIS with cutline and feathering for Landsat-8 imagery

1 - I have two scenes Landsat-8 RGB 6/5/4 and I need to mosaic them: 2- This is my cutline in polygon format that will smooth the overlapping area: 3 - So, I need to create a mosaic with feathering ...