Same scale for multiple rasters' symbology of a "Stretched" style
September 09 2011 |
12 comments
Categories:
Symbology
Goodday,
I have four rasters that all have different scales associated with the min/max values. I need to represent all of these rasters with the same color ramp applied to the same scale value for all four rasters so that similarities and dissimilarities can be noticed between the four rasters easily. Is it possible to do this as a "Stretched" symbology where I key in the max/min values for the color ramp to be applied to?
Mapping Center Answer:
The better way to do this is to use a color map file. In that file you would define the colors as RGB values and you would define the values associated with each color. That way, for all of the rasters, the same values will have the same colors. Here is a link to the online help topic about how to create a color map file.
BTW, not sure if you remember me but hello from a former UoR student. We had dinner almost exactly a year ago with Tony Turner after he gave his agent-based modeling colloquium. :) -Andy C18.
i have IDW techniques applied raster Image in different month ...kindly any one suggest me how to do it ????
for example when i plot january month image,my color ramp scale will fixed (i took scale , from 0 to 700,scale interval 100),in my data January month highest rainfall 70 and lowest rainfall 0...as per as my clor ramp show 0-70 yellow color .so my image color should be yellow thats i want ...but i can't ...plz suggest me ...my mail id -jhashouvik@gmail.com
http://downloads2.esri.com/MappingCenter2007/ask/OregonAnnualPrecipitation.zip
Download and unzip the file, then open it in PowerPoint and play the presentation.
You will see that the same legend is used for all time periods. The colormap file we used is also displayed in the legent -- the legend shows the full range of temperature values for all time periods and the associated colors in the color map file. That one colormap file was applied to each time period. Therefore, whatever the range of temperatures was in the time period, it used that range of colors in the colormap file, and if temperatures were out of the range for that time period, they were not used.
I think this is pretty much the same thing that you want to do -- so the answer is the same -- use a colormap file that contains the full range of values and apply it to each time period. Only those colors that are in the range for the time period will be used.
For example when we do Interpolation techniques than image color should be come continuously....i want like this type of color in my image ....how to do it ??....plz suggest me
0 255 255 0
10 0 255 255
Then you can linearly interpolate the 9 values between the colors 255,255,0 and 0,255,255:
0 255 125 0
1 230 112 25
2 204 100 51
3 178 87 76
4 153 75 102
5 127 62 127
6 102 50 153
7 76 37 178
8 51 25 204
9 25 12 230
10 0 0 255
To get these numbers, take the range of one of the R, G, or B values (e.g., 0 to 255 – the range is 255), divide by the number of values in the range (in this case, dividing by 10 gives you 25.5), then add that value to the lowest number and use that as the next number in the color definition (in this case 25). Then add the value again to get the next color definition (25.5 + 25.5 = 51). And so on. Do this for all the R, G, and B values.
Note that you cannot use anything except whole numbers in the color definitions, so either round up or down – it won’t make much difference in the color you see whether you round up or down.
I hope this helps!
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