1
vote
0answers
20 views

Postgis Raster Unions Color Issues

Can someone explain to me what I am doing wrong here as I think I do not properly understand postgis raster bands. I have a set of geometries that I want to merge with a raster and created a raster ...
1
vote
2answers
72 views

In ArcMap 10.2, exporting raster as .tif with “use renderer” and “force RGB” still produces inaccurate colors

I have a DEM and my aim is to change its color ramp using ArcMap, then export this colored raster as a geotiff (8 bit). I checked "use renderer" and "force RGB" options but the results are not good ...
1
vote
2answers
71 views

Retrieve Elevation from Color in Raster DEM

This might turn out to be a newbie question, and that would be because I'm fairly new to GIS work, but extensive online searching, asking associates with some basic GIS knowledge and hours in various ...
0
votes
0answers
36 views

qgis's georeferencer renders my white map with a translucent blue tint, can I prevent this?

I'm running QGIS 2.0.1-Dufour on MacOSX and when loading a PNG or TIFF into qgis as a raster its always getting rendered with a blue tint. Here's what it looks like before being loaded into QGis's ...
1
vote
1answer
41 views

GEOTIFF Binary File with Color Display Issues

I have a GEOTIFF in QGIS that shows values of 0 and 1 and I want the 0 values to have no fill so that background vector layers can show through and so I can easily overlay things in a print composer ...
1
vote
0answers
39 views

Color blending/compositing in web mapping frameworks?

The color/layer blending capabilities of QGIS 2 produce marvelous results. Blended rasters are especially nice to look at. Blending is, to me at least, a better way of combining layers than mucking ...
1
vote
1answer
242 views

How to get custom color palette in rasterVis plot3D in R?

I am trying to insert an RColorBrewer palette to visualize an elevation raster in R using the rasterVis function plot3D. The rasterVis reference document shows the following parameters: plot3D(x, ...
2
votes
2answers
165 views

Convert ASCII Grid Colorized to Raster

I have an ASCII Grid file + .prj file and can visualize this in qGIS. I can colorize it by going to properties and using a Pseudocolor Ramp. However, I want to export this now as a TIFF / Raster. ...
1
vote
4answers
134 views

Batch visualization of raster (grid) files

I have about 100 raster (grid) files (in the "ascii grid" format) of drought index. All cover the same area of interest but at different times of year. I need to create images from the grids with ...
3
votes
1answer
66 views

What defines a Class in the Heat map plugin?

What defines a Class in the Heat map plugin? As in: "Black holes like that are usually caused by raster values exceeding the range of the color ramp. Try adding another class with a higher associated ...
4
votes
2answers
197 views

How to create a colormap where colors diverge at value 0 in QGIS?

I calculated a raster as difference of two other rasters. Now I want to create a colormap where one colour represents negative values and one colour positive ones. The two colours should become ...
1
vote
2answers
146 views

Put color for raster data(aspect.tif) on QGIS1.8.0

I create aspect.tif from DEM file. I could put the values(0 to 360)from contrast enhancement. I could set color from color map(freakout or Pseudocolor). In here, the data is shown by only 4 colors. I ...
4
votes
1answer
363 views

Recoloring geotiff for visual presentation

I have a rather big Geotiff. It is the mosaic of four RapidEye satellite images. They are all a bit bland/grayish. When combined I would like to freshen up their colors so that they are more visually ...
0
votes
1answer
123 views

Coloring pixels based on values

I have an image where pixel values are integers, they go from 0 to 6 and I also have some 999. I want the value 999 to be transparent, which I could achieve by myself. I would like values 0 to 6 to be ...
2
votes
1answer
198 views

How can I apply correct colours to an elevation raster?

I have a problem to display elevation data with pseudocolours. The channel 1 is from -3.40282e+38 to 149.717 . A colleague used 1.7. and it looks like it should (from blue to Red) when I use QGis 1.8 ...
2
votes
2answers
977 views

How do I use ranges for raster colour map in QGIS

I have a raster layer in GeoTIFF format, with continuous data values between -1 and +1. For the colour map, I would like... >0 to be green = 0 to be grey <0 to -0.25 to be pink <-0.25 to ...
3
votes
2answers
580 views

How can I apply stretch in ArcGIS 10 Image Analysis Window?

I need to apply stretch to ArcGIS 10.1 exported raster. The best way to accomplish this task: Image Analysis Window, because there are fine tools to equalize raster data. 1 - This is my IRS-P6 24m ...
2
votes
2answers
450 views

How do I create a negative to positive value raster with neutral 0?

I have a raster layer with a band with values from -137 to 9229. I want to create a color scheme showing how far from 0 the positive numbers are in one color, and how far from zero the negative ...
3
votes
2answers
824 views

ImageMagick's convert program changes PNG file format so that color/alpha info doesn't survive GDAL

It appears that ImageMagick's convert program changes something in my PNG file that causes GDAL processing to mess up the color and/or transparency bands. My original PNG file gets processed ...
4
votes
2answers
3k views

How to create a color ramp in ArcGIS10 where the zero value is represented by white?

I have a simple problem which (to me) seems to be difficult to solve in ArcGIS. The map I plot is a GeoTIFF with emission data. I use a default algorithmic color ramp (rainbow) to do so. Now I would ...
6
votes
1answer
582 views

How to modify the colors of a raster map to use only one color in varying shades?

I have a raster map in GRASS containing elevation values. I want to display the elevation values in only one color (specificaly blue) but in varying shades of blue. I tried the options in r.colors, ...
1
vote
1answer
236 views

Creating color table file in PCI Geomatica

What is the simplest way to create a stand-alone color-table file in PCI Geomatica (PCT or STR)? I have some classified imagery with values ranging between 0-255 and I would like a way to ...