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Hanno
United Kingdom
143 Posts |
 Posted - 25/07/2016 : 10:01:51
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This boils down to the core and most elementary issue in dealing with maps (and digital map making)!
By their very nature and by definition, 'maps' are a scaled representation of the real world. Scales are therefore fundamental in 'map making'.
Images like aerial photography or scanned old maps should have a 'calibration', because they are 'maps'. A 'calibration' is the means by which the software knows the scale of the map. A map without a scale is just an image.
In the old version one could indeed open any old image and use Map Maker Pro as an illustration tool. In this new version you are now warned that you are about to make a non-nonsensical map. To work with such an image in Map Maker, (a map making tool, not just an illustration package) you must calibrate it. If you do not know any real world calibration data (location & scale), just opt for the calibration utility: "Single point and know scale"
Use for example XY=0,0 and scale 1:100.
Top menu,
Utilities,
Bitmap Utilities,
Calibrate image
etc.
There is one huge advantage in working with digital maps which is this:
What you are conceptually doing with a calibration is that you are 'draping' the image on to the virtual world in its exact spot. In digital map making, with calibrated (or 'geo-referenced' map data) we are always working in a 1 to 1 (1:1) virtual earth. The further you zoom out (to say 1:25.000 scale) the less accurate your drawings becomes (but the larger the area you can see).
Working in the 'virtual world', 1:1, means that you can 'layer' different maps on top of each other, and if these maps (like possibly your historic rail way maps) cover the same area, you can observe changes.
And it gets even better:
'Google Earth' is precisely this: a 'virtual copy of the real world' All maps and aerial photography are 'calibrated', 'geo-referenced'. And that means that if you do a proper job with your calibration, you can 'layer' your files on top of this virtual Google Earth.
Try it:
Top Menu,
File,
View in Google Earth ( it has to be installed on your computer first of course!)
Hanno |
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Uncalibrated jpgs - MM4
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