Howto Produce Map for MapMap: Making BMP Map Image From Non-BMP Map
This howto discusses how to produce map image in format suitable for
MapMap from a map in non-standard, or vector, format. This includes all
vector map formats (including PDF) and any propriatary format. You do not
need to follow this procedure if you have map in BMP, JPEG, GIF, PNG, or
any other raster format which your graphics editor can directly open.
To follow these steps, you will need viewer for the map, raster graphics
editor and a bit of patience and effort, as procudure essentially consists
of grabbing map's image screen-by-screen in the viewer, and then re-fitting
it in the graphics editor.
Extracting image
- Open PDF in Acrobat or other PDF viewer and set zoom at the level
where all details intersting you are decently visible. You should
take into account resulting image size (for example, if your screen
has resolution 1024x768 and the map scrolls up to 8 screens horizontal
and up to 5 screens vertical, its projected size is:
(8hscreens*1024pix_per_h)*(5vscreens*768pix_per_v)*(8bits_per_byte/4bits_per_pix) = 15Mb ,
so, you may need to find compromise between detailedness and size).
- Set map to the left upper corner and consecultively copy each screen of it to
your graphics editor. Do like following:
- Press "PrintScreen" key on your keyboard, that will put the entire image of
your screen into keyboard.
- Paste it into new image/file in your graphics editor. For example, in PhotoShop
that will amount to creating new image (it will chose dimensions based on clipboard
contents automatically), and pasting data to it.
- Scroll map in your PDF viewer horizontally, and if needed vertically,
by fullscreen (for this, tap
on the scrollbar between carret and scroll arrow of appropriate direction).
- Repeat until you process entire map.
- Once you finished grabbing individual screens, you need to crop them of off
user interface decorations, so only map graphic remains. Be careful to do it
precisely: do not leave decoration's border and do not chop map's graphics. Setting
zoom at 200% or higher is helpful.
Some
graphics editors allow to repeat operations on new images: once you set crop frame
properly, you can apply it to each image with just several mouse clicks. If your
editor supports this capability, as it can save you some effort.
- Finally, you need to fit all the screens into single map image. Usually, you do
this by creating new image of required dimensions (you know how to calculate them),
and copying the screens one by one there, aligning one properly before proceeding
with the next. Again, appropriate zoom is helpful. You should keep in mind that
most viewers scroll with negative reserve, leaving in each screen narrow strip
of previous one, so you should not just make sure that there is no white space
between screens, but that they are really align perfectly. This is not really hard
with maps, as objects on them usually have sharp borders. In short, use your eyes
as guideline. Last note: when you are really close to perfect hit, it is better
to do final movements not with mouse which is not very precisise, but with cursor
keys, which usually moves object by single pixel.
- Once you have done fitting screens into single map, you may want to crop extra
border, if any. Well, now you have raw map image. What is left before you can use
it with MapMap - converting the map to 4-bit format. Go on with Preparing
image for use with MapMap Howto, which starts where this Howto ends.
Extracting objects
In arbitrary case, extracting information like objects' names and positions
is very hard or not possible, so you may very well fallback to generic
(i.e. manual) method. However, for some selected format such a procedure
may be available:
(c) 2002-2004 Paul Sokolovsky