Questions tagged [digital-image-processing]

The field of raster image processing

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18
votes
1answer
30k views

Panchromatic Image association with high spatial resolution

How and Why is a Panchromatic Satellite Image associated with high spatial resolution? I googled and found that it is a single band image, but then why is it called pan-chromatic(All Colors). Does it ...
16
votes
2answers
790 views

completing satellite imagery tiles when data coverage is less than 100%

I want to join several images (>=2) into one "best" image. Best is defined on low cloud cover and high data coverage. An example using free Sentinel satelite data follows. See http://sentinel-s2-...
13
votes
4answers
10k views

Splitting .tif image into several tiles? [closed]

I have an image of size 1GB (.tif), with the width and height 94000x71680. I would like to chunk this image into 20000X20000 tiles so that I can process them. How can I do this?
12
votes
2answers
319 views

Ice type differentiation using satellite data

I would like to classify glacial area by categories of snow (if there is) and ice, but what's most important: between old ice and fresh ice. They have different properties that are possible to ...
11
votes
2answers
810 views

Is it scientifically correct to pansharpen landsat reflectance product with pan band

I need to know if it is scientifically valid to fuse/pan-sharpen Landsat 8 surface reflectance products with pan band of that respective band? Landsat reflectance product details can be found at here. ...
11
votes
1answer
2k views

Multispectral image segmentation for natural-resources applications using R

R has the capacity for image segmentation, although all of the examples I have come across utilize a single band for the segmentation (example). I am interested in combining R's capacity for random ...
9
votes
1answer
2k views

Ditch Extraction using LIDAR DTM (1m resolution)

I'm trying to extract ditches using the LIDAR DTM using the software eCognition but I am actually having a hard time since the paper where I based my workflow entitled "Ditches’ network extraction and ...
8
votes
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 ...
8
votes
1answer
2k views

Novel ways of filling in missing values in a raster

I am looking for robust ways to fill in missing values in some rasters. They all have a single layer. Missing values consist of single pixels to medium sized patches. Rasters are around 1000 x 1000 ...
8
votes
0answers
330 views

Executing bidirectional dijkstra on TIFF image?

Can anyone indicate an example of how to do this? Link, tutorial etc... I started a discussion here about how to load a TIFF image like a graph nicely answered by @sehe. But, in this post the image is ...
7
votes
1answer
467 views

Counting rocks of different sizes on shoreline using ArcGIS Desktop? [closed]

I have a 5cm resolution geotiff image for a shoreline. I need to count the number of rocks in three classes (e.g., >6 feet, 3-6 feet, and <3 feet). I don't have any point cloud data. What will be ...
7
votes
3answers
739 views

Extract DEM and DTM information from LIDAR image using E-Cognition

I´m trying to extract DEM and DTM from a LIDAR file. Currently, I rasterize the image but don´t know which algorithm I need to apply to obtain the DEM and DTM information in different models to be ...
6
votes
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 ...
6
votes
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 ...
6
votes
2answers
1k views

Unsupervised raster classification using GDAL

Is there an equivalent in GDAL to the Arcpy ISO data unsupervised classification tool, or a series of methods using GDAL/python that can accomplish this?
6
votes
3answers
2k views

How to generalize training data for a random forest classifier?

I am working with a random forest classifier in eCognition (new with eCognition 9.0). The image shows 8 NAIP tiles I am attempting to classify using approximately 100 training points. The training ...
6
votes
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 ...
5
votes
2answers
449 views

Calibrating Landsat Level-1 Precision and Terrain (L1TP) corrected data?

My study will involve Landsat OLI, ETM+ and TM scenes for forest biomass change assessment (Time Series Analysis) using different vegetation indices and textures. According to the official site https:/...
5
votes
7answers
8k views

Failed to create signature file

I've no clue how to solve this issue in the exercise that I'm trying to perform. The point where I'm stuck is 4. "Create signature file as LandsatCompS.sgs". I've done what it says in the exercise. I ...
5
votes
1answer
600 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 (...
5
votes
2answers
322 views

Pattern search in satellite imagery

I would like to search for the specific buildings (polyhouse in my case) on the map like the one shown here Are there any free options available which can give me lat and lng of such shapes/features ...
4
votes
3answers
302 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 ...
4
votes
2answers
2k views

Specifying pixel depth in ModelBuilder?

I have a simple model that calculates the NDVI from bands 3 and 4 of a raster dataset. The input bands are 8-bit unsigned, whereas the default output NDVI is signed 32 bit. How can I specify the ...
4
votes
1answer
3k views

Reading zipped ESRI BIL files with Python

I asked the question below on StackOverflow, but haven't received any feedback there yet: I have precipitation data from the PRISM Climate Group which are now offered in .bil format (ESRI BIL, I ...
4
votes
1answer
901 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 ...
4
votes
1answer
693 views

Atmospheric Calibration for Landsat 7 ETM+ Gap Filling

This is for thesis work involving mapping of above-ground mangrove forest biomass using Landsat 7 ETM+ imagery. I am assessing correlations between biomass with vegetative indices, e.g. NDVI, and ...
4
votes
1answer
720 views

Questions regarding the processing of mosaic Landsat 8

Approximate Translation of Original Question: A question of theoretical and practical about the mosaic of satellite images. I have 3 different months of Landsat images, which need to accomplish the ...
4
votes
1answer
2k views

Performing Random-Forest Classification of 10cm Imagery for species-distribution in R (no point-shapes)? [closed]

I'm trying to classify 10cm-resolution images with the RF-package. I do this to separate some species in the forest, seen on my images. While I was searching for an answer, I found the following ...
4
votes
1answer
98 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 ...
4
votes
1answer
352 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 ...
4
votes
0answers
119 views

Appropriate resolution of images for image classification? [duplicate]

I am attempting to perform image classification on some maps that I have in PNG format. This classification is failing due to there being too many many pixels in the training samples (I appear to be ...
3
votes
3answers
1k views

How to extract surface from air photo avoiding trees and buildings?

I am working with Drone air images. These are geotiff images and clearly portray trees and buildings. I need to first classify the image according to land cover distribution, then need to remove the ...
3
votes
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,...
3
votes
3answers
886 views

Extract values from raster based on points and pixels adjacent to the point

I have an issue. I have a set of points (n=~2000) and I would like to extract the pixel values from multiple rasters (a single-raster solution is also ok) for location of that point as well as that of ...
3
votes
2answers
2k views

automatically geo- and ortho- rectify raw Landsat data using DEM

I have a dataset of 20 Landsat scenes (MSS, TM, ETM+) for 20 years (one scene per year). Scenes are in WGS 84, EPSG 32634 coordinate system and I can easily project = geometrically correct them to ...
3
votes
1answer
2k views

How to extract vegetation polygons from Imagery using Python?

I have been trying to roughly polygonize vegetation areas from Imagery (RGB). I tried using Iso Cluster Unsupervised Classification (Spatial Analyst) but it is still too detailed for my purpose. I ...
3
votes
2answers
52 views

Detecting 12bit images in 16bit

Setting For the purpose of a machine learning algorithm I'm tying to automatically scale images of arbitrary bitdepth to unit interval, i.e. I want to map pixels from [0,2x] to [0,1] simply by ...
3
votes
1answer
1k views

Image classification using google satellite images

Currently our expert user classifies locations by viewing the Google earth satellite image of a location. They consider circular areas of a 5km radius at a set zoom level. They evaluate the image for ...
3
votes
1answer
99 views

Performing Supervised Classification on Sentinel Image using ArcGIS Desktop?

Is it possible to perform supervised classification on Sentinel Satellite Image with the minimum error. I compared two raster, one being the manual classification of an area using Photoshop CS6 and ...
3
votes
1answer
124 views

Is preproccessing a Landsat scene necessary for image classification?

I am classifying Landsat TM scenes for the entire Chesapeake Bay as part of my Master's research. Scenes have been collected from 1986 to 2016 in 5 year increments for my area of interest. I recently ...
3
votes
2answers
159 views

Pansharpening influence on analysis

Using as an example Landsat 8 bands: Does pansharpening band enhace only visible range and therefore can I use it only for analysis connected with visible spectrum? Or I can pansharpen every possible ...
3
votes
2answers
534 views

Looking for real-world DJI Phantom 3 Professional sample geo-tagged images for testing

I am looking for sample DJI Phantom 3 Professional imagery for testing purposes with the Drone2Map for ArcGIS Beta software. So far I am finding the application very polished and easy to use but I am ...
3
votes
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 ...
3
votes
1answer
942 views

How to improve classification accuracy for 3-band (RGB) imagery?

I am hoping to extract some simple vegetation features (sagebrush) from 1m 3-band (RGB) NAIP imagery. Unfortunately, there is no near-infrared band available for this dataset and I need to use this ...
3
votes
1answer
503 views

How to do separability analysis in eCognition?

Can I use eCognition to check which bands are more helpful to separate individual classes and to get output result? If so, how can I do this?
3
votes
1answer
599 views

Retrieving exif tags from GeoTiff with GDAL?

I work on toolkit that automatically classifies data from a bunch of aerial cameras. Each camera uses geotagging to store position and time metadata in EXIF tags. When I use GDAL (I use version 2.0....
3
votes
1answer
219 views

ArcMap Image Analysis Window - functionality is grayed out

In ArcMap's Image Analysis Window, none of the tools are available even though I have a raster selected in the window. I do not have Editor turned on. I can't identify why the Processing tools are ...
3
votes
1answer
63 views

Globbing in Windows to process images - how do bash loops look in DOS?

I'm doing some batch image processing with imagemagick on OSX using this line: for file in $(cat all.txt); do convert -crop 50X50@ +repage +adjoin "$file" "$file"_tile_50x50@_%d.jpeg; done It takes ...
3
votes
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 ...
3
votes
1answer
296 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, ...