Hot answers tagged color
First off, let me say how much I appreciate this question. I have seen so many example of inappropriate colour palettes applied to digital elevation models that it's good to see that people are thinking about this. There are some really good answers here too, but here is my opinion. I doubt that there is a universally good palette but rather a group of ...
Here is a really simple example library(raster) data(volcano) volcanoR <- raster(volcano) #making colors below 100 red and above 180 blue in this example breakpoints <- c(94,100,120,140,160,180,195) colors <- c("red","white","white","white","white","blue") plot(volcanoR,breaks=breakpoints,col=colors) You just need to pass the plot a vector of ...
For thematic maps, the handy Colorbrewer has an ArcGIS plug-in, ColorTool The built-in styles also contain lots of professionally selected color palettes and ramps that you could repurpose for other needs. To look at the styles without having to dink around in ArcMap, you can view them in PDF form
You can change the styles of the shape file in the layer properties. Double click the layer and select style. Select Categorized style and choose a field you want to visualize. Remember to classify your values before leaving the dialog.
I usually come at this question from the angle of "what is going to enhance, and not obscure, my data?". Tufte talks about the some of the uses of colours in maps: to label, to measure, to represent, and to enliven. Choosing DEM colours is usually mostly for the latter (enlivening) - to make them look nice. For example, the default 'atlas coloring' of many ...
I think the literal answer to your question is "not really" (aside from things like blue=water or blue/red=Dem/Rep). It depends on how/what other data is displayed on a map and the map's purpose whether, for example, county boundaries are a light color or dark color. There are plenty of places where color choice is discussed. Some examples of books (I'm ...
Expanding on one of themes in Simbamangu's very good answer: the basic problem with elevation shading using any colours at all other than neutral greys is the inescapable tendency for us to interpret meaning from the colours. For example a common rendering technique is to use deep greens for the valley bottoms, progressively lighten as one travels upslope, ...
You can use data defined properties for this. Use the style tab on the layer properties and click the expression button to the right of the color. In there you can use the function color_rgba( red, green, blue, alpha ) to create the color. All values need to be between 0 and 255. Example: color_rgba( 255, 0, 0, ( 1 - "transparency" ) * 255 ) This will ...
I think you're missing something in what johns has said in his comment. When you are looking at the symbology for the raster there are two renderers to choose from - stretched and RGB composite. However, on the RGB composite settings there is also a stretch option. You need to set this to None. There are a couple of ways to export a raster. If using the ...
In GRASS shell type: > r.colors map=elevation color=rules > 0 white > [your maximum elevation value] blue > end
Research on color preferences (I don't remember seeing things specifically for head-aches) tend to be mixed (see MacEachren's How Maps Work for an overview). I personally do not like when there are multiple, fully saturated colors (and that example gives me a headache as well), but user studies typically do not find unanimous preferences, e.g. some people ...
You can download the ColorBrewer styles for use in ArcMap through the ArcScripts site
As a follow up to Matthias' answer, in QGIS >= 2.12 you can use a data defined fill color with the expression: set_color_part(@value, 'alpha', ( 1 - "transparency" ) * 255 ) What this expression does is takes the original polygon color (@value) , and replaces the alpha channel (opacity) with the value calculated from the field). This means you can set ...
If you only need color scheme of ColorBrewer, http://arcscripts.esri.com/details.asp?dbid=14403 is a workaround while waiting for new update of ColorTool.
You can have a different approach for that problem. 1)from line width: line width units=map units. 2)map scale rules: close maps=thick lines, far maps=thin lines. In QGIS you can do both.
Yes, it can. Phong shading is a sum of ambient, diffuse, and (specularly) reflected light. The ambient portion is represented by the usual map of the DEM. The diffuse portion is computed with a hillshade. A "hillshaded DEM" is a weighted sum of ambient and diffuse reflections. The formula for the reflected part of the image can be computed in terms of ...
This seems to work for me on a -1.0 - 1.0 NDVI raster Double click on the raster layer in QGIS table of contents/layer list Click "Style" tab (1st tab on the left) Select "Render as" -> "single band gray" and "Single band properties" -> "Color map" -> "Colormap" Click "Colormap" tab (2nd tab from the left) Click "Add entry" and add the following entries: ...
If your data consists of points and you would like to create a heatmap, QGIS has a handy heatmap plugin. There is a great tutorial on creating heatmaps from point data here. Often it is useful to display categorical data in your maps. In this case, I would recommend using the integrated QGIS ColorBrewer located in the style manager. There is a great ...
As Vladimir has suggested, you can do that by making sure they are using the same color table. You can do this by loading both DEMS in QGIS, then right clicking the DEM that has the color table you like and copying its style. You then select the other DEM, right click it and paste the style.
As @Baltok alluded to, you are trying to have the Selection on a particular layer be treated in the same way as other layers are, with respect to drawing order. I think that by default, and design, ArcGIS makes the Selection override the symbology of anything that is underneath it, as a means of making it easy to find the selection. Since you are selecting ...
So, I use swiss hillshade for most of the maps I use (here's a screenshot from California's Central Sierra) and tend to use a red/beige-grey theme that loosely follows the philosophy that Simbamangu described of not being too in your face (ie, it's not super colorful and in some spots is even a little drab, but the information is conveyed and I can layer ...
In addition to what has been mentioned there are a few more things to consider. You can enhance the 3-dimensional impression of the map by not only varying the color hue but also the saturation, brightness and vibrance. Saturated colors will appear closer and are suitable for mountain tops while the lowlands and valleys can be colored rather unsaturated or ...
The best plugin to use to do colour ramps on rasters is the 1-band raster color table v1.10 plugin. Found in the plugin installer under the same name.
Hmmm, i would take a different approach. I would build a .vrt raster catalog (you can do so from QGIS raster menu) from all your DEMS, then assign a single pallete to that vrt file which acts as a single layer.
Greyscale maps and illustrations are still important because colour incurs an additional cost in printing and is most effective on a glossy paper which poses problems for collation in automated and print-on-demand services. Therefore, it is rare for books to have more than a few colour plates. It is not so much an issue of technology, rather it is ...
you can use something like this: symbols = self.vlayer.rendererV2().symbols() symbol = symbols symbol.setColor(QColor.fromRgb(50,50,250)) Good job!
Ok I think from your question that what you need to do is create a style which can be applied to the same data set for the same colour ramp. Assuming this is what you have meant. For example, take rock classification from the British Geological Society. Once you have classified each rock type into a relevant colour. Open the layer properties by clicking ...
It might well be possible with QGIS 2.0 to do this. In the Style->Symbol Selector you can choose Data defined properties There you can assign the color based on an expression which also can calculate based on different schemes, CMYK among others. You would have to transform your values to a format accepted as input there. Source: ...
In the Data Frame properties, click the Frame tab and change the background color:
My favorite effect for readability/aesthetics is a "gradient fill". If you are using ArcGIS software, this effect is fairly simple to implement... Here is a good blog post from ESRI's team at the Mapping Center: Quick tint bands
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