Questions tagged [digital-image-processing]
The field of raster image processing
271
questions
24
votes
4
answers
30k
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?
- 361
20
votes
1
answer
36k
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 ...
- 585
16
votes
2
answers
2k
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-...
- 631
13
votes
4
answers
1k
views
Should I always choose Sentinel-2 atmospheric-corrected imagery?
Sentinel-2 imagery is available in the default L1C form, or in the atmospheric-corrected L2A form.
I haven't been able to find a L1C - versus - L2A comparison that would provide the pros and cons of ...
- 8,302
12
votes
2
answers
2k
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. ...
- 3,496
12
votes
2
answers
505
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 ...
- 739
11
votes
1
answer
3k
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 ...
- 51.7k
10
votes
0
answers
479
views
Executing bidirectional Dijkstra on TIFF image? [closed]
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 ...
- 121
9
votes
2
answers
18k
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 ...
- 567
9
votes
3
answers
8k
views
Create pandas DataFrame from raster image - one row per pixel with bands as columns
I have a raster image with 3 bands. I would like to convert this image to a csv file where each row will be one pixel and each column will be one band, so that I can easily see the three values each ...
- 2,139
9
votes
2
answers
3k
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?
- 772
9
votes
1
answer
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 ...
- 91
9
votes
1
answer
9k
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 ...
- 956
8
votes
2
answers
971
views
"Copy" Image coordinates to another image that is nd.array
I have image with three bands. I have script predicts the first band pixels values by using the two other bands and in the end generates an image.The generated image is at the beginning pandas table, ...
- 2,139
7
votes
1
answer
782
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 ...
- 87
7
votes
3
answers
3k
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 ...
- 51.7k
7
votes
2
answers
5k
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 ...
- 545
7
votes
1
answer
4k
views
Filling in missing values in raster using R
I am looking for a robust way 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 ...
- 1,087
6
votes
2
answers
738
views
Applying HDR (high dynamic range) rendering in QGIS
I want to automatically (without manual adjustments) apply HDR (high dynamic range) rendering to Sentinel-2 satellite images so that the image can distinguish between very bright objects (e.g. clouds, ...
- 7,116
6
votes
1
answer
7k
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 ...
- 4,321
6
votes
1
answer
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 ...
- 61
6
votes
2
answers
2k
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 ...
- 161
6
votes
5
answers
1k
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 ...
5
votes
2
answers
777
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:/...
- 1,198
5
votes
6
answers
18k
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 ...
- 99
5
votes
2
answers
4k
views
Computing Excess Green Vegetation Index (ExG) in QGIS [duplicate]
I have to process the image for Sugarcane row detection and extraction.
Sample image is accessible from the link: https://github.com/AndresHerrera/croprows_generator_pa_v2/tree/master/droneimages
I ...
- 537
5
votes
1
answer
629
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 (...
- 3,376
5
votes
1
answer
419
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, ...
- 313
5
votes
0
answers
312
views
Processing drone Images of body of water?
I took some pictures of a body of a body of water using a multi-spectral sensor attached to drone. When trying to process the image using Pix4D, more than 50% of pictures were unable to calibrated.
...
- 339
5
votes
3
answers
2k
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 ...
- 51
4
votes
4
answers
4k
views
What is lost when converting 12 bit imagery to 8 bit?
SPOT 6/7 satellite imagery is captured with a dynamic range of 12 bits per pixel per channel (ref). However almost all of the SPOT imagery I have seen in use has been 8 bits per channel, and split ...
- 28.2k
4
votes
3
answers
335
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 ...
- 53
4
votes
2
answers
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 ...
- 51.7k
4
votes
1
answer
1k
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 ...
- 956
4
votes
1
answer
2k
views
What does cumulative count cut actually do?
I have a grayscale satellite image (16-bit image) which is dull (low brightness). When I apply cumulative count cut from 2 to 98 percent (Properties -> Min-Max Setting -> Cumulative count cut), it ...
- 41
4
votes
1
answer
5k
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.
4
votes
1
answer
2k
views
Extracting vegetation polygons from Imagery using ArcPy [closed]
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 ...
- 1,360
4
votes
1
answer
832
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 ...
- 43
4
votes
1
answer
197
views
Removing dropped line using fourier transformation?
I've noticed a 'dropped line' in only one band of SPOT MS image, as seen similar to added example. By applying fourier transformation to the band in SAGA GIS, the dropped line can be clearly spotted ...
- 1,198
4
votes
1
answer
818
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
1
answer
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 ...
- 147
4
votes
1
answer
3k
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....
- 3,583
4
votes
1
answer
652
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 ...
- 71
4
votes
1
answer
732
views
Generating Hough transform (Hough line transformation) of binary image using QGIS
How do I generate a Hough transform (Hough line transformation) of a binary image in QGIS?
I tried in GRASS and I got Error: unable to fetch interface description for command
I found from the link: ...
- 537
4
votes
1
answer
170
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 ...
- 289
4
votes
0
answers
132
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
4
answers
2k
views
gdal : How to restore georeferenced DEM's metadata?
EDIT: this question was not properly answered. An actionable answer should be provided. Maybe involving gdaledit -mo or gdal_translate in.tif in.vrt together with xml manipulations, or any operation ...
- 2,653
3
votes
3
answers
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 ...
- 699
3
votes
2
answers
4k
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,...
- 31
3
votes
2
answers
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 ...
- 3,376