topic Can i extract polygons from image (jpeg) file? in Geoprocessing Questions

Can i extract polygons from image (jpeg) file?

Adnantariq — Wed, 01 Jun 2011 10:32:07 GMT

Hey all,

I have Jpeg file having geological map of city which has many polygons each with diffrent colors, now i want arcmap to extract all polygons and convert them into shapefile ?? is there any way out??

i have tried by manually draw polygons but there are many empty spaces between them how i can remove these white/ silver spaces??

i have attached the jpeg and can send by mail the shape files if one can help me
please reply to me ..

here is my ID if one can contact me there
adnandani@gmail.com

Re: Can i extract polygons from image (jpeg) file?

TimothyHales — Wed, 01 Jun 2011 11:37:35 GMT

You might try the Iso Cluster Unsupervised Classification tool to reclassify the image. Depending upon the output, you may need to reclassify the output to combine like values that represent a polygon area. Then convert the output of the reclassification to a polygon. I am not sure how accurate the output may be as the quality of the input raster is a key factor.

Re: Can i extract polygons from image (jpeg) file?

Min-DongChang — Wed, 16 Nov 2011 19:01:18 GMT

I found a solution through another thread, however wasn't able to find the exact link. But using Spatial Analyst, run the => Local => Combine tool on the image that you want to convert. This will assign a unique number for each unique color and create a new raster. You can then use the Conversion Tools => From Raster => Raster to Polygon tool. You still need to manually assign the attributes manually accordingly once the polygon feature is created.