2
votes
0answers
35 views

Choosing the map scale (1:nnn) for the given raster dimension

Starting points: let define the raster image size, say: 1800x900 pixels I want draw my own raster image map - by drawing polygons e.g. like "draw line from pixel with coordinates x100y100 to pixel ...
0
votes
1answer
60 views

problem in scale of projected raster

I have a shapefile (my basin limit) and one raster file that I projected it to the shapefile coordinate system and set its cell size to 1000m(area=1Km2). my basin area is 5400 Km2 and it should ...
0
votes
1answer
182 views

Error in raster displays of NoData cells when “zoomed in” past scale 1:3,000,000

I looked around GIS stack exchange and ArcGIS Help pages and didn't find anything on this issue. I have encountered an error in how Arc displays a Raster file (.TIF format) at different scales. At ...
1
vote
1answer
102 views

How to calculate size of a pixel for a scanned map?

A land use map has a scale of 1:150000. The map is scanned at a resolution of 150 DPI. What will be the surface area in m square represented by each pixel in the resulting easter map?
1
vote
2answers
136 views

Rasters added to mosaic dataset only display at large acale

I have a set of 357 rasters in .jp2 that I've added to a mosaic dataset. All but 7 of them display properly, but the 7 only display at larger scales, around 1:6500 and under. I've tried adding them ...
1
vote
2answers
534 views

How do I import OS raster tiles into QGIS at the correct scale?

I have some tiles of OS raster mapping and their associated TFW georeferencing files. The GR files are in the same folder as the raster data and have the same names, ie TQ21.tif/TQ21.tfw. In QGIS ...
0
votes
1answer
97 views

Integer rasters referring to the same scale

I'm using ArcMap 10. I want to display the area of simulated avalanches. I want this area to be divided in different colors depending on the thickness of the deposit. I managed to do that. But I want ...
3
votes
1answer
161 views

Sensitivity analysis for coarse scale GIS epidemiological model?

I am working on an epidemiological model with disease incidence rate as dependent variable and environmental factors as independent variable. Disease data is available at county scale whereas ...
0
votes
0answers
18 views

Scale factor (constant not linear stretch) GDAL [duplicate]

I need to re-scale a geotiff with gdal. I'm aware that gdal_translate has a -scale function, but i need to actually apply a constant (eg value(x,y) * 100) instead of scale the pixels to within a ...
5
votes
1answer
317 views

Georeferencing a jpeg in QGIS but the scale is way off

I've gone through the really helpful walk-through(s) of how to georeference a jpeg in order to make it a layer, but after inputting the coordinates (either by typing in actual coordinates or clicking ...
1
vote
1answer
107 views

Can I avoid runtime raster interpolation by creating an image pyramid to match the zoom scales?

For image quality and performance reasons, it would be best to perform interpolation of my large TIFF image of the world (10GB) beforehand to all the zoom scales I need to display at so that MapGuide ...
3
votes
1answer
381 views

What are some examples of model-based upscaling of raster data?

Remotely-sensed raster data may be too fine-grained for many purposes. A typical approach to coarsen the grain is to upscale by reducing the resolution. If the data are continuous (e.g elevation, ...