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1
vote
1answer
54 views

Sort colors from light red to dark red

I have the following png image displaying tanker traffic density: The colors are from dark red to light red, dark red means 'lowest density' and light red means 'highest density'. For example, the ...
1
vote
1answer
46 views

Extract all unique values from a RGB raster

I have a .png file in RGB format showing the intensity of ship traffic: For my analysis I need to convert it to a one-band raster with values between 0 and 1 where 0 means lowest density and 1 ...
1
vote
1answer
50 views

Why does the composite raster pixel values not cover the full range of RGB and what does this mean for reclassification after conversion to int?

I have about 30 or so composite rasters in IMG format that I need to 1.) Preserve the date that the raster was created and 2.) Combine all of them. My workflow is: Step 1: raster calculator, ...
2
votes
0answers
83 views

Can I export the RGB values from an ArcGIS layer symbology?

I've got a point layer in ArcGIS that has 100 specific color codes based on the name of the store. I'm trying to export the RGB values for these colors (along with the name value it's tied to) so I ...
3
votes
1answer
40 views

How to digitize RGB TIFF automatically

Is it possible to digitize RGB TIFF by color - I need to select all the vegetation cover types from the image below, which is a part of an aerial photography of an island ...
2
votes
2answers
52 views

How to color lat/lon points in given RGB data?

I am using QGIS on a Mac. I am working with hydroacoustic data for mapping and interpreting the seafloor. Data are collected, processed and interpreted. The result is a txt file with Lat and Lon in ...
0
votes
0answers
34 views

RGB Imagery Layer - Feature Extraction

I'm looking for information on Feature Extraction from the Ordnance Survey Mastermap Imagery Layer. This could be technical information, research papers or just sound advice from folks on this message ...
0
votes
2answers
101 views

From RGB raster to grayscale

I have been searching for a way to rasterize shp files (Unexpected output when using gdal_rasterize) and it worked with a little help. Now, my code is first rasterizing the largest sip file and than ...
2
votes
2answers
784 views

How to extract X Y coordinates and RGB from pixels using python in QGIS?

I'm trying to white a Python plugin in QGIS (2.2) to get, for each pixel of a raster image, its X Y coordinates, as well as, its RGB (3 bands) values. At first I opened the raster file using: rlayer ...
0
votes
0answers
64 views

How to change area inside mask to different RGB Value in ECW Format with FME

I have 3 Band RGB ECW Raster files and would like to change all the RGB values within the masked area to 0,0,0. I am using the SpatialFilter to set the masking area and thought that I could use the ...
0
votes
1answer
88 views

How to iterate RGB raster layers in ModelBuilder?

I have an RGB raster that I'm calculating color-based indices from. When I do the calculations manually, I can select a certain band of the RGB raster to calculate. I need to do the same operations on ...
0
votes
0answers
52 views

How can I add/define a legend for RGB images in QGIS?

I have a RGB image in QGIS that is the product of some raster analysis (e.g. QGIS's relief operation, results from sound/traffic models) to which I want to add a legend. I'd like to denote several RGB ...
0
votes
0answers
119 views

ArcMap- Create a symbology from RGB with colors name

I have a number of features loaded on a mxd I would like to create a script or model builder to assign each row containing a value in the coloum "ENTE" with a RGB color which must be represented in ...
2
votes
1answer
274 views

How to reclassify a raster (tiff) with multiple bands?

i have a raster file containing information about the windspeed average for the year. My purpose is to reclassify the 15 classes based on their rgb-composite. The color is the only information given. ...
2
votes
1answer
276 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 ...
0
votes
1answer
331 views

Basic raster map questions

My bigger problem is to convert a raster map to polygons. I've found some questions that give info and I'm trying to use GRASS GIS as part of that. However, I'm having some basic problems and I can't ...
2
votes
1answer
107 views

Display a raster stack with several bands in ArcGIS?

I have already made a raster stack (5 bands in one TIFF) of my multitemporal Landsat images in R and have also clipped a smaller region of every raster stack for each image. Now I want to do some ...
0
votes
2answers
2k views

Multi-Band (RGBA) into single band raster

I have the raster which contains 4 bands (RGBA), which ilustrates the pupulation (traffic) density. I want to convert it to the simple gridded ascii, however I'm getting in the trouble when I try the ...
5
votes
1answer
634 views

How to force RGB in a raster in QGIS?

I have rasters in 1 band 64bits float that represent real data values and for which I can set min and max using the stretch to min and max option in QGIS. I would like to convert these rasters to RGB ...
6
votes
1answer
3k views

ArcMap 10 - Extract raster cells from imagery based on RGB value

I've got some aerial photography (format: IMAGINE Image) which is detailed enough to see to fire hydrants and a shapefile of fire hydrants which was digitized based on some CAD data. My project is to ...
3
votes
0answers
248 views

How to symbolize vector features using RGB values stored in three fields?

I need to symbolize a vector layer in Arcmap based on RGB (or HSB - can do either) values found in fields in the attribute table. I'm working with up to 10 different datasets, each with over 100 ...
2
votes
2answers
3k views

GDAL: Convert specific RGB (GeoTIFF) color to transparent

I have an RGB GeoTIFF file and I want to convert a specific RGB colour to transparent. I would like to use GDAL for doing this, but external Python scripts are also an option (though I haven't learned ...