Rotation angles, how to measure

FV
Posted By
Frank_V_Mitchell
May 8, 2005
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822
Replies
4
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Closed
When straightening an image is there a way to measure the amount of rotation required instead of guessing?

If I could draw straight lines (on a layer) along straight surfaces in the existing image and PE would tell me what the line angles were, I could work it out the required rotation angles from that

The Help menu says I can draw lines but I don’t find it very helpful. I’ve searched the rectangle, pencil and other menus but can’t find anything useful.

Is what I want to do possible? If so, where do I find the tools?

I’m using PE3 on a Dual Mac G4

Thanks,
Frank
RR
Raymond Robillard
May 8, 2005
As far as I can tell, you’d need a little mathematics to get there (the number of pixels versus the distance from the point of origin, that sort of thing).

But, there’s an easier way. Activate the grid, then select your image Command – A (CTRL – A) and Command – T (CTRL-T). Enlarge the image window to make the corners visible and click outside one of the corners. The mouse cursor will change for a double headed arrow. Click and drag. Using the grid, you’ll see instantly if your image is straight or not.

Ray
RF
Robert_F_Carruth
May 8, 2005
Frank,

Here’s one method by one of the forum’s best:

Grant Dixon, "Leveling the horizon with elements" #6, 20 Mar 2005 10:31 am </cgi-bin/webx?14/5>

A forum search for "Angle" should turn up similar techniques. If you have access to any of Scott Kelby’s books on Elements at your local library there is a step by step explanation there.

Bob
FV
Frank_V_Mitchell
May 8, 2005
Thank you Bob, that will do nicely!

Regards,
Frank
CW
Colin_Walls
May 8, 2005
I have 2 suggestions:

1) Display the grid. That gives you horizontal and vertical baselines.

2) If you draw a line [using the Line tool] and have the Info palette on view, while you are drawing you can read the angle of the line in the Info pane.

There is a 3rd, much better, method, if you make your own prints: don’t rotate in PSE at all. Just cut/mount the photo print to correct. The reason that this is better is that odd angle [not multiple of 90 degrees] rotation require non-linear resampling, which degrades an image. How much depends on the image, but pixels are destroyed and created in the process.

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