Plumb-Bob 4+

• What Plumb-Bob can do?
With Plumb-Bob you are able to transform an usual picture in a plan view.
It is sufficent to know 4 key points of the plan to rectify.

Plumb-Bob is a perspective rectifier useful in many fields: architectural survey, building renovation, furnishing design, estate agents, and it represents a real completion for the metric / photographic survey.

• How it works?
There are few ingredients needed:
A picture not too big (2 MegaPixels are enough), where 4 known key points are clearly visible.
The real coordinates of the 4 key points. These points have to lay on the same plan we want to survey and they have not to be on the same line (not collinear). The more distant the points are and the less will be the margin of error.

• Lens distortion correction tool
Plumb-Bob provides also a tool for correcting lens distortion (an aberration that causes straight lines to curve). The algorithm can use correction parameters, for a large number of lenses, from the Lensfun database (http://lensfun.sourceforge.net), which is included in the software.

• Results
As result you get a rectified image you can use as template in your CAD application, in order to retrace the drawing.

• More…
Once you have made the rectification, Plumb-Bob knows the parameters needed to know to convert every point on the image in real world coordinates.
You can get real distances directly on the picture.