Localised Zooming/Shrinking

[bugbear]

I'm making up a route map for a sponsored cycle
ride, where the emphasis needs to be on making the
correct turn at junctions, and the road length/shape
in between are not (as) important.

The journey is long enough that a complete uniform map
at "good resolution" is not feasible.

So I want to shrink the map between junctions, and expand
in at the junctions. Sort of like varifocal glasses.

So I guess my "dream" solution would be to have a second
layer where the intensity is amount of zoom, draw a
white blob where the junctions are, leave everything else
alone, press a button, and get my map.

Back on planet real, this sounds like some kind of morph.

But I don't have a start-image and end-image. I'm trying
to CREATE my end image.

Can anyone help?

BugBear

[Jerryb]

hi,

intersting.... one possible idea.... hopefully i can explain it....
i assume your using a map making program.....

1. make a copy of your overall trip map
2. zoom in and make a copy of the critical turning junction points.....

now...
3. in your PS ...put each one on a seperate layer......
4. on the layers that have the critical turn points... resize that image.., possibly down to about 2x2" , enough to where it small but readable.....
5. at that point you then move these critical turn points any where on the overall map and you can add a arrow from the critical turn point to the point on the overall map..!

that my idea.... hopefully it usable and meet your needs maybe some one else has a better idea

Originally Posted by bugbear

I'm making up a route map for a sponsored cycle
ride, where the emphasis needs to be on making the
correct turn at junctions, and the road length/shape
in between are not (as) important.

The journey is long enough that a complete uniform map
at "good resolution" is not feasible.

So I want to shrink the map between junctions, and expand
in at the junctions. Sort of like varifocal glasses.

So I guess my "dream" solution would be to have a second
layer where the intensity is amount of zoom, draw a
white blob where the junctions are, leave everything else
alone, press a button, and get my map.

Back on planet real, this sounds like some kind of morph.

But I don't have a start-image and end-image. I'm trying
to CREATE my end image.

Can anyone help?

BugBear

[bugbear]

Originally Posted by Jerryb

hi,

intersting.... one possible idea.... hopefully i can explain it....
i assume your using a map making program.....

1. make a copy of your overall trip map
2. zoom in and make a copy of the critical turning junction points.....

now...
3. in your PS ...put each one on a seperate layer......
4. on the layers that have the critical turn points... resize that image.., possibly down to about 2x2" , enough to where it small but readable.....
5. at that point you then move these critical turn points any where on the overall map and you can add a arrow from the critical turn point to the point on the overall map..!

that my idea.... hopefully it usable and meet your needs maybe some one else has a better idea

Yep, that makes a practical map, but it's not nearly as cool as my "dream map" (insofar as something which doesn't yet exist can be cool)

Any morph experts here?

Oh, BTW (should have said earlier) , I'm Using Gimp on Linux.

Some googling later...

It appears that "whirl and pinch" and "IWarp" are the "sort of things" I need.

BugBear

[0lBaldy]

How are you at Java Script.. I found this on the web... Know nothing bout it! http://valid.tjp.hu/zoom/index_en.html

[Verywierd]

A simpler solution would be to set up the map on a web page, put hot spots at each junction set to pop up a more detailed sectional map in a floating window when you click on it with a mouse.

[bugbear]

Originally Posted by Verywierd

A simpler solution would be to set up the map on a web page, put hot spots at each junction set to pop up a more detailed sectional map in a floating window when you click on it with a mouse.

But I want something to print out, so the cyclists can carry it on the ride.

Unless they've all got iPhones a web site is no good!

BugBear

[Verywierd]

Sorry, I misunderstood. I thought you needed a dynamically changing image. If all you want is to be able to click and inlay an enlarged portion of the map on the main map at junctions, you could try this:

1. Set up your main map.
2. Make a duplicate layer of the map, but enlarged x10 (or whatever factor works for you), then create a black mask. Set opacity to (say) 30%.
3. Make a duplicate of layer 2 (layer 3). Click on the eye icon to deactivate it.
4. Set up a circular white brush or pattern of the size you want for the enlarged view.
5. When all the above is in place, you just slide layer 2 until the appropriate junction lines up, click your brush on the mask at the junction. Change layer to 100% opacity. Merge layer 2 down.
6. Duplicate layer 3 and repeat process - and so on.

Once you are set up, it is just (a) make duplicate layer (b) slide into place (c) click brush (d) change opacity (e) merge down. The actual movements would probably be faster than reading this.

[bugbear]

Originally Posted by Verywierd

Sorry, I misunderstood. I thought you needed a dynamically changing image. If all you want is to be able to click and inlay an enlarged portion of the map on the main map at junctions, you could try this:

Parts of the "main" map would then be fully overlaid, and thus destroyed; hence my desire to use a continuous, but non uniform zoom.

BugBear

[Verywierd]

If you mean something like this, you can do it in PS using the "warp" function. Just use the marquee tool to select a circle around the desired area, call up "warp" and pull diagonally outwards on the grid. Then use the adjustment points to re-align the roads/trails. Sorry, I don't know if GIMP has an equivalent function.

The map I used is not a very good example as the scale is too small (and I wasn't very careful) so I ended up covering or distorting some details, but on a smaller scale map, it should work.

[bugbear]

Originally Posted by Verywierd

If you mean something like this, you can do it in PS using the "warp" function. Just use the marquee tool to select a circle around the desired area, call up "warp" and pull diagonally outwards on the grid. Then use the adjustment points to re-align the roads/trails. Sorry, I don't know if GIMP has an equivalent function.

The map I used is not a very good example as the scale is too small (and I wasn't very careful) so I ended up covering or distorting some details, but on a smaller scale map, it should work.

That's much more like it - thanks for that.

I've been trying to use Warp in gimp (and its cousin, IWarp), but I'm struggling to get good results.

BugBear