[GRASSLIST:4054] coastal photos to habitat map

Dear List:

This is my second time asking the list for another probable newbie problem.

To give everyone a background, we are doing a project that aims to 
popularize the use of open source system and GRASS GIS for coastal resource 
management among local government units in southern Philippines. We are 
still on a pilot stage and we are interested in mapping coastal habitats 
from scanned aerial photos. We are having a hard time knowing the right 
method.

Based from archive search, tutorials and help documents, we manage to 
import Tiff file and rectifying the image using 4-6 control points. 
However, when we open the raster file in the targeted location, all we see 
is a clump of several (30-40) big pixels of varying grey shades. We were 
expecting that the end image will just be the same grey scaled picture 
tilted according to the reference North. From there, we could have 
digitized coastal features as polygons representing various habitats. We 
hope to reach the stage of printing maps for CRM plans.

Has anyone did a similar work or knows how we can do it? Please share us 
some step by step procedure and if possible additional  electronic 
references as we have very limited literature.

Thank you so much,


November A. Romena
GIS Practitioner
Bureau of Fisheries & Aquatic Resources
Philippines