Hi, I'm new to Inkscape and looking for a bit of advice on a project I'm about to embark upon.
I have some quite large bitmap files which are the contour lines from maps built up as strings of dots, as per the fragment attached here, though the real thing is a lot larger.
I'd like to use Inkscape to produce a coloured relief map, i.e. where each of the contour rings have a fill with, say, a darker and darker shade as the altitude increases, as per the random example in the second image attached here.
The approach I'm thinking of is to trace a whole load of objects in Inkscape grouped together in sets (one set per contour height) where each set has its own sub-layer. I'm assuming I can have the layers in height order and the blobs will then sit on each other appropriately. I have a few questions:
1. If I do it like this will I be able to set the colour and blend characteristics of all objects in a particular sub-layer in one go? I expect I'm going to want to experiment with the colour choices and it would be a massive pain if I had to do this individually for every single object.
2. Does Inkscape have any tools that will help me trace objects from the dots in the bitmap base layer image?
3. Is there a fundamentally different way of achieving what I'm setting out to do which would be better?
As far as my experience goes it's not the easiest tasks to learn inkscape.
The trace bitmap cannot extrapolate from dots into a closed line. However you may be able to create some approximation of continuous contour lines in a raster image editor.
Depending on the dot density and how close the contour lines are some manual editing may be necessary.
For drawing the line missing behind the texts -and removing them- manual editing will definitely be necessary.
Once you have continuous shapes, centerline tracing should give a base for further processing.
Would need to add a fill value to them in some way. Either by making them single paths on top of eachother or by combining some into compound paths with "holes" inside.
I'd prefer the first solution.
For the colouring part, there is an extension to interpolate attributes inside a group.
Based on the object's z-ordering you can interpolate between black&white.
After that, can use a colormap filter to try out different colouring schemes.
For the final drawing probably using a filter isn't the best choice so some extension or manual editing would still be necessary.
Here is a quick edit of your example image. Used gaussian blurs and adjusted the contrast.
It'd be a similar solution to trace the original image and dynamic offset the result until the neighboring dots connect, then converting it to a path and simplifying.
However it's much faster to do the same in a raster image editor. Used gimp in the example.
It's nothing close to perfect and still need alot of work to be done.
Have heard some proprietary softwares can digitize such maps with ease in the past but I have serious doubts about it.
Beginners' Questions Building up a contour map
Inkscape.org
Hi, I'm new to Inkscape and looking for a bit of advice on a project I'm about to embark upon.
I have some quite large bitmap files which are the contour lines from maps built up as strings of dots, as per the fragment attached here, though the real thing is a lot larger.
I'd like to use Inkscape to produce a coloured relief map, i.e. where each of the contour rings have a fill with, say, a darker and darker shade as the altitude increases, as per the random example in the second image attached here.
The approach I'm thinking of is to trace a whole load of objects in Inkscape grouped together in sets (one set per contour height) where each set has its own sub-layer. I'm assuming I can have the layers in height order and the blobs will then sit on each other appropriately. I have a few questions:
1. If I do it like this will I be able to set the colour and blend characteristics of all objects in a particular sub-layer in one go? I expect I'm going to want to experiment with the colour choices and it would be a massive pain if I had to do this individually for every single object.
2. Does Inkscape have any tools that will help me trace objects from the dots in the bitmap base layer image?
3. Is there a fundamentally different way of achieving what I'm setting out to do which would be better?
Looking forward to aby help you can offer.
Welcome aboard!
As far as my experience goes it's not the easiest tasks to learn inkscape.
The trace bitmap cannot extrapolate from dots into a closed line. However you may be able to create some approximation of continuous contour lines in a raster image editor.
Depending on the dot density and how close the contour lines are some manual editing may be necessary.
For drawing the line missing behind the texts -and removing them- manual editing will definitely be necessary.
Once you have continuous shapes, centerline tracing should give a base for further processing.
Would need to add a fill value to them in some way. Either by making them single paths on top of eachother or by combining some into compound paths with "holes" inside.
I'd prefer the first solution.
For the colouring part, there is an extension to interpolate attributes inside a group.
Based on the object's z-ordering you can interpolate between black&white.
After that, can use a colormap filter to try out different colouring schemes.
For the final drawing probably using a filter isn't the best choice so some extension or manual editing would still be necessary.
Here is a quick edit of your example image. Used gaussian blurs and adjusted the contrast.
It'd be a similar solution to trace the original image and dynamic offset the result until the neighboring dots connect, then converting it to a path and simplifying.
However it's much faster to do the same in a raster image editor. Used gimp in the example.
It's nothing close to perfect and still need alot of work to be done.
Have heard some proprietary softwares can digitize such maps with ease in the past but I have serious doubts about it.