Get points from polygons with extreme angles

Question

I intend to remove points from a polygons with extreme angles like the image link

I make my buffer like this...

SELECT (ST_Dump(
          ST_Union(
             ST_BUFFER(the_geom, 10, 'endcap=flat join=round')))).geom as the_geom 
FROM mytable

The error is on buffer unions, see the image.

I want to remove that points.

What have you tried, where are you stuck, what language/platform are you using? Is there some code to evaluate? We need to know where you're up to to tell you where to go next. You say PostGIS, but is that SQL or are you accessing the objects via OGR or QGIS etc.. — Michael Stimson, May 05 '16 at 22:43
Please include images locally. Remote links fail over time, making the question useless. Use the edit button to update questions with details requested in comments. — Vince, May 06 '16 at 00:19
I was going to upload the image for you, but it timed out, nicely illustrating Vince's point. — John Powell, May 06 '16 at 06:09
how long those slivers are ? if they are small you can remove them by using st_buffer(st_buffer(geom, 1),-1) . another option is use St_generalize or write script using st_dump , calculate length and angle between points, and then remove unneeded points and re-create line — simpleuser001, May 06 '16 at 10:03
These are sometimes known as "cutbacks," btw. And they're not a reliable way of identifying these anomalies. — jpmc26, Mar 06 '18 at 00:21

score 2 · Answer 1 · edited May 06 '16 at 13:33

2

Thanks simplexio, I used your idea: st_buffer(st_buffer(geom, 1),-1)

Buffer 10m: st_buffer(st_buffer(geom, 10-1),1)

edited May 06 '16 at 13:33

ArMoraer

answered May 06 '16 at 13:07

Paulo Pires

1 Answers1