Via Vector One, I discovered Kelso’s Corner, a blog by an award-winning cartographer for the Washington Post; it’s been added to my blogroll at left. In turn, that blog pointed me to Color Oracle, a free Java tool (Windows, Linux and Mac) for evaluating the effects of several kinds of color blindness. I was surprised to learn that 8% of the male population suffers from some variety of color blindness (that’s about 1 out 12), so keeping their limitations in mind is important. Run the program, and it lets you choose between the three most common kinds of color-blindness: Deuteronapia (most common), Protanopia (rare) and Tritanopia (very rare). It changes the coloring of the entire monitor to reflect what it would look like if you had that specific kind of color blindness, and plasters a big label on the screen to let you know which kind of color blindness is being simulated. Click anywhere on the screen to return to normal color. The program also lets you get a screen capture of the color-blind view.
Continue reading ‘Evaluating Map Graphics For Color-Blind Viewers’
I’ve posted previously about Tom Patterson’s shaded relief maps, and he has a new one out. The Physical Map Of The World extends out his earlier Physical Map Of The Coterminous United States to cover the entire globe with shaded relief topography, “natural” colors to represent biomes, and key physical features labeled:
You can view the imagery online in a Zoomify interface, but as with his other imagery, he also provides free downloadable versions of this imagery in CMYK JPEG, and Adobe Illustrator files with the labels and graticule.
Via the always excellent Map Room.
The Map Room posts on the University of Toronto’s efforts to put the three-volume Historical Atlas of Canada in online format; it’s not complete yet, but still worth a look. Maps and graphics don’t appear to be downloadable, but some of the data is (e.g. climatic data). Screen grab:
Native Subsistence 1000 CE to Contact
The US Government’s National Oceanic And Atmospheric Administration (NOAA) has placed online 21,000 maps, downloadable in both JPG and MRSID high-resolution formats (see this post for several free MRSID viewers and converters). The maps are mainly historical nautical maps dating from 1655 to 2001, but there are also a fair number of Civil War battlefield maps, many of them contemporary with the war, and not all of them nautical in nature.
Continue reading ‘Historical Nautical And Civil War Maps’
Yesterday, I posted about a NOAA site where you can download Raster Navigation Charts (RNC), maps of coastal and inland waterways. The charts are currently only available in BSB format, which many GIS programs can’t handle; I linked to a few free viewers that will let you view the maps, but not export them. They’re also only available in the Mercator NAD83 projection/datum. Peter Guth (the author of the terrain analysis GIS MicroDEM) let me know about a free utility available from NOAA called the Digital NOAA Nautical Chart Reprojector. It lets you re-project the BSB maps into one of 32 projections (e.g. geographic or UTM) and over 100 datums, then exports the chart in BSB, RAW or TIFF format with a world file; the latter virtually every GIS program and graphics editor can open. It looks like it was originally a command-line utility, since a DOS box pops up when you run the program, but it now comes with a GUI:
The Input File and Output File dialog windows are a bit clumsy to use until you figure them out, but for the input file, you’re looking for the .kap file that came with the zip file you downloaded from the NOAA mapsite. Choose the desired output parameters at right, including choice of output file format (TIFF here), projection (UTM) and datum (WGS_84). The GUI doesn’t set the UTM zone automatically, but you’ll see the West and East Bounds for the map in the Input Info window at left, and can use those as a guide for setting the correct UTM zone with the Projection Parameters dropdown at right. In this case, clicking “Run” will create the TIF file specified as the output file, along with its worldfile. The file extension for that worldfile will be .tifw; if your GIS program doesn’t accept that, try changing it to the more-commonly seen .tfw extension.
NOAA also has a free extension called Chart Viewer that lets you open BSB charts natively in ESRI’s ArcView and ArcGIS, and Leica Geosystems’ Imagine.
NOAA’s Office Of Coast Survey has downloadable copies of regularly-updated RNCs (Raster Navigation Charts). The updated charts are in BSB format, not supported by many GIS and graphic software programs, but there’s a list of links to free and demo software packages capable of displaying BSB files in georeferenced format (like Caris EasyView and GPSNavX). The site indicates that NOAA will issue GeoTiff versions of these charts at some unspecified point in the future, but those charts will not be as regularly updated as the BSB charts will. Selection is either by chart number or a graphical viewer (requires Java):
To choose a chart for downloading in the graphical viewer, click the “Selection Mode” button at the top, then click on the rectangle defining the chart area (clicking inside the rectangle does nothing). Click “Add To Cart” at left, which adds it to a list of charts to be downloaded. When you’re done selecting charts, click on “Place Order”, and follow the directions to get a zipped copy of the BSB chart (response time to the button-pushing may be slow):
Native map projection for the georeferencing is Mercator NAD83, in meters.
The University Of Idaho’s Repository Of Primary Resources lists over 5000 worldwide websites describing primary resource sites holding maps, books, archives, and other original data sources. Websites are organized by geographic area and then by country in several different formats. Some of these repositories offer viewable/downloadable copies of their holdings.
Another useful gateway is the Map History / History Of Cartography site.
A few more links to online resources to help with choosing colors for maps and related graphics:
Color.org - Upload your own graphic image, then select colors from it by moving your cursor over the graphic and clicking on a color block. Add colors to a color scheme, or find complementary colors. Interface is a bit confusing, though, and there’s no help file.
ColorSchemer - Click on a single color, or enter the RGB/Hex value, and get a set of 16 complementary colors.
Whatsitscolor - “Whats its color is an image-color processing utility that will evaluate an image and give you the image’s primary and complementary dominant colors of an image, how many visually unique colors are in an image, and the top ten visually unique colors in an image. Extremely useful when creating any type of designs around an image. The more colorful the image, the better the results. Results will display your image on the best suited background for that image.”
See some of the other posts on this blog about color tools (1, 2, 3).
Via Lifehacker.
