[SEL] A Welding Question/Now Software

[Jerry Evans]

At 06:00 PM 20/08/2007, you wrote:
>From: "Elden DuRand" <edurand at mchsi.com>
>Subject: Re: [SEL] A Welding Question - Apprentices
>Jerry:
>I took a look at your pages.  Interesting!  I also learned a bit about 
>painted background plates.
>Question:  Does your software have the ability to remove the distortion 
>caused when photographing a curved plate?  I know this distortion can be 
>diminished by using a long lens and backing off but the distortion will 
>only be lessened.
>Take care - Elden

Hi Elden,
         No I do not have any magic software like that. I also doubt if 
Photoshop could do that because you would need some kind of 3D Modelling X 
photo editing software to do it perfectly - you would also need to know the 
distance that the "curved end" is away from the front and a few other 
measurements.
         What my software can do (and so can Photoshop) is "distort" a 
picture so it follows that it can also take a distorted picture and (to a 
certain degree) straighten it. I do not use this method.
         To give an example as simply as possible: Imagine a square plate 
photographed from an angle (to the one side) . The resultant flat picture 
will have the edge nearest the lens appearing longer than the edge on the 
"further away" side (perspective). With digital imaging software you can 
"drag" the far corners outward until you have them the same length as the 
near edge and the pic will then appear to be rectangular. I have 
occasionally done this with a rectangular plate but never an oval plate.
         To make my explanation easier to understand I have put an example 
here:
<www.oldengine.org/members/evans/plates/distort/index.htm>

         It takes me many hours to draw out the artwork and I do not charge 
for this time. That is why I prefer a good pic to start with. I can also 
work (within reason) from a lousy picture but it takes so much longer.
         I hope this answers your question.

Keep the revs up (or down)
Jerry Evans
Near Johannesburg in Sunny South Africa.
Etched Brass Engine Plates made to order:
See:
www.oldengine.org/members/evans/plates/index.htm
or learn how to finish off your plates
www.oldengine.org/members/evans/plates/finish.htm