[comp.graphics] Image Processing Coastal Geo Data

pape@agcrr.bio.ns.ca (Andrew Pape) (06/15/91)

I am doing a project with the Environmental Marine Geology dept. of the
Bedford Institute of Oceanography in Dartmouth, Canada.  We are doing
coastal geological/geographic research and are looking at coastal
erosion in parts of Eastern Canada and the arctic.  

We have a series of aerial photographs taken along the coast of
Newfoundland, and we want to scan them in and manipulate the images with
Image Processing software.  I'm fairly new with the world of Image
Processing.  We are using UNIX, Mac, and MS-DOS machines here, and are
looking for suggestions of software packages or techniques that can do the job.


We want to do the following with the bit-mapped images:

Manipulate the images so that we can identify the coast-line (water
level), and filter out all extraneous data (in-land features, water
levels) so that only the coast remains in the image. This can be a
complicated job, because the water line is not always really obvious
when the land and water profiles are gradual.  A cliff is really east to
identify and manipulate with image processing software.

Compare the images with scanned photographs from ten years previous
with the eventual goal of identifing erosion over the ten years.

Compensating for the geometric errors (skewing, rotation) in the photograph (if it was taken at an angle rather than perpendicular to the ground) by finding 
constant reference points in each of the two photographs (buildings, etc.) 
and "rubber sheeting" the image (stretching it with some sort of
algorithm so that the reference points match).  

Comparing the coastline of the two images (with equal reference points) and
and making a calculation of the difference.  This could be like a
subtraction operation that may result in a plot and numeric calculation
of the difference between coastlines.  

Save and print the filtered images (containing only coatline and some
reference feautures) and the plots that are a result of the subtraction
of one image from the other. 

The fractal analysis may be a way of simplifying images for easy
comparison.  If we were to find the fractal dimension of the coastline,
we could compare them numerically with the fractal data.  I don't know
very much at all about fractal analysis.  

Any suggestions?  Thanks.