9 replies to this topic

[SaultDon]

The source data was the Terrain Resource Inventory Management - Level I; DEM points and contours.

The resulting grid had a cell size of 5m.

I used the hillshading toolbox (from ESRI resource centre) to get a nice set of overlays. This was suppose to create a 'swiss style' shaded relief. It was kind of close.

My first time venturing into photoshop to really try and touch up a hillshade, it went smoothly (no pun intended).

Current workflow inside photoshop -> Import GeoTiff -> Tone -> Median -> Reduce Noise -> Gaussian Blur

The tone step was used to redistribute my max and low values, i think I have a minimun 5% black, and max 25% black. Shades of gray.

Median I never used before and really liked! This tool generalized the surface creating a continuous surface effect. This tool is the primary factor for the generalization that occurs I am thinking so far.

Reduce noise was recommended, but I couldn't get the results I wanted, the image was getting very grainy and areas of little elevation change were becoming discrete so I skipped this tool, but will play with it more as the results in the higher elevation areas was of course desirable as discreteness would be preferred in steeper areas.

Lastly, good old Gaussian Blur... No clipping of image required, it was exported from ArcGIS without any external white/black space. This allowed me to override the original by clicking Save and applying a LZW compression to the TIFF (from 900mb to 72mb).


This will be printed on a 36"x24" paperspace.


I will be providing some detailed documentation in the following days on my blog (link to post) to outline this process.

Any feedback is needed please. I am concerned about too much saturation, it seems a little dark still. What can I do in photoshop to correct this even more? Perhaps adjusting the tone near or again at the end... Also note that I had to apply a gradient overlay (white:transp right:left) to more evenly distribute the tones, the whole right half of the image which contians the lower elevations was far darker then the rest of the image regardless of my touch ups in photoshop.


Software: Photoshop CS4 (also have Illustrator with MapPublisher), ArcGIS 10.0

[Charles Syrett]

I don't think there's any way to generate a generic step-by-step process to edit a relief image within Photoshop, such that it will work for any project. There are just too many variables. That being said, the tools you mentioned (Median and Gauss) are among those that I use the most.

Charles Syrett
Map Graphics
http://www.mapgraphics.com

[SaultDon]

I don't think there's any way to generate a generic step-by-step process to edit a relief image within Photoshop, such that it will work for any project.
http://www.mapgraphics.com

Thanks for the input Charles, and I do apologize for the confusion, maybe it's in the title and should of read something like

my photoshop workflow for making this shaded relief,

I didn't mean to propose a standardized process, for the very reason you have pointed out I did this specific hillshading a couple of times, not following the same process more than once.


I am hoping for some insight from the carto pros. Specifically, from my questions at the end of the post, like opinions on the overall tone (too dark?) etc.

I did post this in the map gallery forum (looking for feedback on my map design) but it got moved over here, perhaps because of the blog reference or I could be experiencing trouble understanding my own prose...

In any regard, looking at my original post, and seeing the tools I used in Photoshop, is there any that I am using that you can offer pointers on, like some common thresholds you don't exceed when using gaussian blur for example (like rarely applies a blur over 14px), or tools that I don't know about.

I will continue to research and experiment, as those are the best ways for me to learn. I haven't tried it in Avenza yet so I am heading to their site now to explore my options.

[David Medeiros]

I do a lot of shaded relief and find that I mostly make a few adjustments to saturation & lightness (Adjustments > Hue/Saturation) to get the right overall color tone and density. And then for my work where I'm doing a lot of small scale regional relief I go to the Surface Blur tool to help cut back on relief complexity without over softening the major features (similar to Median it seems). I keep the variables low for the most part. After that I use a very low Gaussian Blue (1 or 2 usually). This softens the overall relief and gets rid of the "photo" feel that hi res elevation data can have when rendered. Incidentally the Gaussian Blur usually takes care of most "noise" in the image. I have never had to use the Despeckle or Reduce Noise commands and find that they usually introduce more grain than they take away.

I haven't ventured out of that workflow much and like you would like to hear what others do for their relief or maybe for specific relief effects? I'm sure there are as many tricks as cartographers out tthere.

[Adam Wilbert]

I posted a quick video on Vimeo a couple of days ago showing how I export hillshade tiffs now from ArcMap, without any Z-scaling madness. Perhaps it's obvious to others, but in short, don't export map, export data! http://www.vimeo.com/17552652 (view full screen for 720p details)

Donovan, You mentioned using the ESRI swiss-shading toolbox. If memory serves me, the toolbox just uses the raster calculator to combine the DEM and hillshade. I've found much better and more flexible results by doing the same thing in Photoshop. Just export your original DEM, add it as a new layer in Photoshop on top of your hillshade, and set the blend mode to multiply. Then you can apply a Curves adjustment layer to the DEM and modify the strength of the effect non-distructively. You can go back and tweak it at any time!

One other toy in the Photoshop toolbox that I've been having fun with lately is the Lens Blur filter. If you use the original DEM as the depth mask, you can adjust the amount of blur based on elevation:

 LensBlur_a.png   527.9K   84 downloads


And when combined with the DEM as a "Swiss" overlay:
 LensBlur_b.png   475.24K   90 downloads


Finally, I've been experimenting with merging multiple hillshades at different angles using the various HDR (High Dynamic Range) tools out there. (one is built into PS CS5, the other is Photomatix). So far it sort of approximates manual multi-directional hillshading, although in a way that can be automated programmatically.

[SaultDon]

Well, this is my first attempt at really enhancing a hillshade outside of ArcGIS as I consider myself more familiar with GIS than with Cartography so your input and various techniques were insightful.

I changed my data sources from TRIM (too much detail and processing power required at my scale) to the 50k DEMS from Geobase.ca

I ended up experimenting making two hillshades, one generalized, the other using the HDR as Adam suggested.

David, I never got into messing with the Hue/Saturation as these were in grayscale, and I used a combination of Level and Gradient Map to help with tone and max/min values, what do you think would be the best practice? To use Hue/Saturation or a combination of the Auto Level and Gradient Map? I am just not sure what the pros and cons are of these two processes compared.

The Surface Blur was tricky for me to get balanced results like you mentioned so I gave up on that for a now and went to the indiscriminate Gaussian Blur. But I am going to explore this tool more.


Adam, you're right about the export data thingy. I usually don't export map to get into a graphics program, when I rarely get the chance to go there, because of the limitation you have pointed out (random resampling). You're method works, as does designating the output in the Hillshade Tool to TIFF (bit depth is handled in Environment Settings as is TIFF Compression instead of directly in the tools UI).

I ditched the swiss hillshade toolbox from ESRI and was feeling that my own hillshade from scratch would me more enlightening; it has been.

The curves adjustment sounds interesting.
My next step is going to be to develop my own Hypsometric Tint based on Land Use (surface cover type) and create a gradient using associative colours. And by non-destructively, you mean it would be applied on-the-fly so it could be tweaked later on without permanently applying a new gradient to the DEMs stretch?

I like your Lens Blur filter effect, it really reinforces what the hillshades generally are meant to do, give a sense of depth perception, where things closer to the viewer (higher elevations) are clear, and low lying valleys become blurry, perfect! I don't think I'm there yet, so another note on things to do.

So below are what I am left with now, top two images being the before and after of trying to create a generalized shaded relief, and the bottom shows what the results of the HDR are.

 hsgrid_s.jpg   630.29K   107 downloads

The top row was produced from the NWW direction at 45 deg. This created some saturation in the steep areas that would help enhance contast from flat > steep.

The HDR on the bottom row is from a natural shining direction more NEE and raised to 65 deg because I wanted to limit the amount of loss of detail in steep valleys. The HDR is an amalgamation of 4 angles 360 (0), 15, 30, 45

[razornole]

I think the key word that Adam used was "curves Adjustment LAYER" or more precisely an Adjustment Layer with the curves command. Layers are the true power of Photoshop

When I create a hillshade I work with three layers. The hillshade, a b/w DEM, and my hypsographic tint. I combine all three of those layers using the multiply command. Usually I add a bit of transparency to each layer to get the right feel. If that doesn't get it I'll add a curves adjustment layer to play around with my black point, white point, and midtones to whichever of the three layers needs an adjustment.

I personally don't blur the valleys, but that is just a matter of taste/preference. To me the valleys hold the most important element, water. Therefore they should be discernible. I create my figures and grounds with my DEMs, both the b/w and hypsographic tint.

hope that helps,
kru

[Kimi]

If you have dem dataset, you can create a shaded relief image with Geographic Imager on Adobe Photoshop.
http://www.avenza.co...ating-shaded-re

Just a quick note

[SaultDon]

If you have dem dataset, you can create a shaded relief image with Geographic Imager on Adobe Photoshop.
http://www.avenza.co...ating-shaded-re

Thanks for pointing this out, I will be exploring the Avenza products in the near future here. I tried them in some college courses I took and liked them.

It will be a learning curve for me as I am not entirely comfortable yet within PS/Ill so the blog will definitely help, appreciate it.

I am used to processing data in ArcMap and then exporting in some manner to a graphics program. Never done any mosaicing/projecting/hillshading outside of ArcGIS so I will be curious to see how Geographic Imager can handle some of these functions, or at all.

(the only limitation with mosaicing geobase DEM's is they don't always edge match completely and introduce small strips of NoData that need to be filled/interpolated) Can Geographic Imager do this? Just trying to understand how much processing will need to occur in ArcGIS before it makes its way to Adobe/Avenza.

I'm sure PS may be able to with some sort of built in algorithm similar to the clone tool? Often accuracy and obtaining reliable results both visually and tabular are important to me.

[Kimi]

(the only limitation with mosaicing geobase DEM's is they don't always edge match completely and introduce small strips of NoData that need to be filled/interpolated) Can Geographic Imager do this? Just trying to understand how much processing will need to occur in ArcGIS before it makes its way to Adobe/Avenza.

I'm sure PS may be able to with some sort of built in algorithm similar to the clone tool? Often accuracy and obtaining reliable results both visually and tabular are important to me.

Hi! I am glad that you tried Geographic Imager during college. Our newest version may look differently from the one you know We have been adding a lot of new features with the recent releases of Geographic Imager. It will be a learning curve but if you evaluate or purchase a license, you will have a full support from us during the evaluation period or during a year from the purchase. You can drop us a line if you have any question about it

As for the missing data ... That's a good question. Unfortunately, there is no Geographic Imager tool to do it at this moment (I will send this as a feature request to our development team) . Meanwhile, you might want to use PS clone tool to fill the "no-data" pixels (usually it is in transparent). Thank you very much for your good question

You might try to take a look at our evaluation version of Geographic Imager first when you have a chance. Please feel free to drop us a line if you have any question then

Best regards,
Kimi