Questions tagged [digital-image-processing]

The field of raster image processing

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13
votes
4answers
11k 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?
1
vote
2answers
4k views

Supervised image classification in QGIS

Is it possible to do supervised image classification in QGIS? I require it for the estimation of cover management factor (C factor) in USLE
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 ...
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 ...
6
votes
2answers
2k 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?
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 ...
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 ...
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,...
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 ...
18
votes
1answer
31k 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 ...
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 ...
3
votes
2answers
1k views

Gdal: How iterate through all pixels of a raster image?

Given a topographic raster image. How to iterate through all pixels of this raster image ? Solution preferably with gdal, in console. Some other libraries/script could be installed. Related: Gdal: ...
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 ...
0
votes
0answers
193 views

Writing code to add calculated image to display in Google Earth Engine?

I wrote a code for Land Surface Temperature (LST) from Landsat 8 images in google earth engine. I have successfully calculated the following steps, NDVI, fractional vegetation (fv), emissivity (EM), ...
0
votes
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 ...
3
votes
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 ...
2
votes
1answer
291 views

Channel swap when reading created image with Gdal

I use a function on python (3.5) to create GTIFF with GDAL: def array2raster2(fname, matriz, geot, proj): drv = gdal.GetDriverByName("GTiff") dst_ds = drv.Create(fname, matriz.shape[1], ...
2
votes
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....
0
votes
2answers
90 views

Relative Radiometric Normalization of multisensor Landsat Level 2 images using R

For my time series analysis, i need to use images of the three Landsat sensors (TM, ETM+ and OLI). I chose the already atmospheric corrected surface reflectance/Level-2 products. Due to the ...
0
votes
1answer
306 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. ...