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17

Use Bilinear Interpolation resampling during display You can somewhat improve the display by changing the resampling method used from the default Nearest Neighbor to Bilinear Interpolation. Layer Properties -> Display Tab -> Resample during display using: Bilinear Interpolation. This effect works best with DEM and the default black and white color ramp. ...


15

The proper name for those old-style shaded relief maps is "Hachure maps". I agree that they do look very pretty, even if they are less useful for actually conveying elevation than contour maps. According to that Wikipedia page, the rules for drawing Hachures are as follows: The hachures are drawn in the direction of the steepest gradient. The ...


9

Arcmap's on the fly hillshade, the method described, is quick and dirty and was never meant to replace the hillshade result from Spatial Analyst and/or 3D Analyst. Although the same term is used to describe both they are not the same at all. To create a true hillshade without Spatial Analyst you might try GDAL's gdaldem: gdaldem hillshade dem.tif shade.tif ...


7

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 ...


7

For relief shading in GRASS, better use r.shaded.relief. It comes by default with light from west to east. Like this (SRTM example): For my perception the valley looks ok in this example. The colortable comes from r.colors (there are "terrain" and "srtm", see here for examples of these color tables).


6

If you are looking for a good looking hillshade that takes some time to create, but is great for larger projects where it will get a lot of exposure, you might try the Swiss Hillshade Method - it requires 3 layers, but you can then export them to one georeferenced tiff to save space and for portability. This method DOES require Spatial Analyst, I believe, so ...


6

This doesn't help with your goal unless you're willing to do some coding, but Michal Migurski recently did some experiments in automating hachures, which were built on by Eric Fischer.


6

I usually post-process a copy of the raw hillshade in some external graphics editing program that I can directly over-write (save, instead of save-as) Photoshop and GIMP are two that come too mind. The process in a nutshell I follow: Import GeoTiff'd Hillshade -> Tone -> Median -> Reduce Noise -> Gaussian Blur Your geotiff should be accompanied with a ...


5

It's possible. From the ArcGIS Resource Centre blog by rajnagi: An alternative to overlaying tints on hillshades. This involves several steps, first of being to convert the DEM to an RGB based raster. This is done by "exporting" the raster to a new dataset after you've applied the desired colour ramp. I'm posting the article contents below as sometimes ...


5

There's nothing wrong with this hillshading and the coloring certainly is not the problem. We are experiencing a common, well-known phenomenon: our visual processing inverts depth and height when the terrain appears to be illuminated from below. (Look at the image again while standing on your head: it will appear correct.) That's why it's best to place ...


5

Since hillshade is just an overlay, you can do it anyway that gives you the desired result. However, the usual way to emphasise the terrain is to apply a vertical exaggeration. In ArcGIS you use the 'Z-factor' in the hillshade tool to do this as per the documentation here. You multiply the z conversion factor by the exageration factor. If your z-units are ...


5

A few thoughts: A previous answer correctly recommends resampling during display to smooth out the irregularities in the hillshade. This is primarily used for cartographic effect when you are finishing a map. Use the Image Analysis window to run a 5x5 smoothing window over the image Find better elevation data. 10 m NED Data is available for the ...


4

When you say in item #2 "can I create my effect with creating a Hillshade layer (without using Spatial Analyst)", do you mean alternate applications for creating a hillshade? If you want to use an application outside of Spatial Analyst, I just recently learned about (but never have used) the "SEXTANTE for ArcGIS extension" (free), which allows users to ...


4

I have always been instructed to increase the z exageration when doing hillshade. I just tried 100 on mine and it seems a bit extreme. Also changing the stretch type makes a big difference in the look of hillshade. Since you are talking about how it looks you might also look at this help item. esir help Which says that hillshading iis applied at the display ...


4

Which hillshade module, Martin? In QGIS Master there are two under the Raster menu: Raster -> Terrain analysis -> Hillshade and Raster -> Analysis -> DEM(Terrain models) If you haven't already done so, I should try the second one (set 'Mode' to 'Hillshade'). Also, tick the 'Creation Options' box and enter 'TFW' under 'Name' and 'YES' under 'Value'. Doing ...


4

If your DHM is a ESRI ASCII grid file, you should definitly give Dr. Jennys Terrain Sculptor a try: http://terraincartography.com/terrainsculptor/! Look also at this post for converting to ESRI ascii grid: http://freegeographytools.com/2010/converting-dem-files-to-asc-format-for-terrain-bender-creating-matching-raster-overlays


4

I suppose that it is the result of r.shaded.relief. Have you set the correct resolution of your region of work (resolution of the SRTM layer, Res: 59.74514451 here) ? Resolution of the SRTM layer: Resolution of the region: Elevation; r.shaded.relief without grainy surface with the correct resolution


3

Why not use the SRTM dataset to find out where you actually have the shadows? In the case you are referring to you might find that shadows are cast by clouds or other interference giving you a wrong (biased) basis for shadows in your landsat imagery. Find the potential shadow areas by using SRTM and make a hillshade raster. Make sure the sun angle and time ...


3

Combined pan-sharpening, contrast stretching, and gamma stretching functions If you have access to ArcGIS (and the Spatial Analyst Extension) you can use the technique described in this blog to "blend" DEM (or imagery) with shaded relief. The main disadvantage of this solution is that it is static; you need to produce an RGB raster from your DEM so if you ...


3

I'm not sure if this is what you are looking for, but you can achieve this using the "Use hillshade effect" option in the layer properties of your floating point raster: Here is a snapshot of the layer alone: And another with imagery underneath


3

As you've probably found, removing clouds from Landsat imagery is not a trivial problem. There is a decent amount of scholarly research about methods for implementing masking and correction for clouds and their shadows. So due to the complexity of this issue, you probably won't find any one size fits all solutions that work perfectly out of the box. That ...


2

You're after elevation coloured, shaded relief? You could start by looking here: http://underdark.wordpress.com/2012/01/19/a-guide-to-beautiful-reliefs-in-qgis/ It's simple to use but doesn't offer much in the way of fine control. The results won't look too much like Imhof I'm afraid :( Hint: If your DEM is lat/lon then transform it to a projected CRS ...


2

On first glance, it seems like the color ramping used is what makes the data look particularly confusing, choosing an appropriate hypsometric tint would make the differences more obvious. You may also want to look at other pre-generated shaded relief datasets for comparison, such as this SRTM-based one. Another thing that would likely help is to add a ...


2

You could generate an HDR image or use GIMP to flatten/merge all those layers. Since you are using open source tools there is also either Luminance HDR or Hugin to do the HDR'ing. You can start by generating world files for your hillshades. In the end you will only need one of the worldfiles to apply to your final hillshade. When doing the HDR, do not ...


2

Based on the image that you included above, and the image you had of your original data from a different post, I think you are encountering the pitfalls of generalizing the raster. First, I will reference a link that was given in comments on one of your previous posts. It is a discussion by @underdark about Generating Relief Maps in QGIS. She is talking ...


2

Check the source tab in the properties dialog. If the dataset does not have a defined linear unit, it can cause issues with spatial analysis tools such as hillshade, slope, etc. You may have to reproject your raster using the Project Raster tool to a different projection. If I recall correctly, DEMs from the NED typically come in a projection that lacks a ...


2

For data from Germany, I would suggest EPSG:31468. Looks like EPSG:3397 has not yet received proper towgs84 parameters. EPSG registry remarks for PD/83: Consistent with DHDN (CRS code 4314) at the 1-metre level. For low accuracy applications PD/83 can be considered the same as DHDN.


2

I solved this problem via the C-Correction (see literature). The C is calculated with the help of a linear regression including the raster data of the Landsat image to correct and the raster data of the hillshade for the scene (C=b/m, b=Interzept, m=gradient). This algorithm is suitable to avoid the black spots (after correction) in the areas illuminated ...


2

I realised you asked about with GRASS, but you can also do this with gdaldem. You can see the process I use for using gdaldem tools with SRTM data.


2

I have managed to find a workaround, although it relies on there being an "extent" shapefile that came with the original DEM. I'd still like to know what I'm doing wrong in my original method, if anything. gdalwarp -co "BIGTIFF=YES" -dstalpha -cutline dtm20m_ext_vg94.shp dtm20m-3785-hs.tif dtm20m-3785-hs-cut.tif This produces the right kind of TIF: ...



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