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keystone perspective parallax

ibear88

New member
I've seen "skwrt.com" for iPhone perspective keystone parallax correction. It appears to do a nice job, but I don't see a non-phone version of it.

I use photoshop and when I make such corrections in PS I have to crop the image.

Is there a Photoshop plug-in or other software that makes such corrections without the need for heavy cropping (and retains pixel quality)? Or, am I doing it incorrectly?

Thanks for the help,
Jeff
 

Jorgen Udvang

Subscriber Member
It seems to me you are doing it incorrectly. Although you'll lose parts of the image, you shouldn't need to do any cropping after the correction. I sometimes do the opposite, enlarge the canvas size after the correction and then cropping to the end result.

The correct tool to use in Photoshop is Edit > Transform > Perspective. I always copy the layer that I'm going to correct to a new layer immediately above, so that I can check the result vs. the original by clicking/unclicking the copy layer.

Before you start, check that your photo is level (horizon or, if horizon isn't visible, a vertical near the centre of the photo). Start dragging outwards, usually at the top, but at the bottom if the camera was pointing downwards. When that is correct, drag upwards on each side to regain correct proportions.

That's how I do it anyway. Others may have different and/or better methods. C1 has an automatic routine for this. Still, I prefer to do it manually.

If there are humans and other vital elements near the edges of a photo taken with an ultra WA lens, use Edit > Transform > Warp to correct the shape of those. That will usually lead to a need for cropping later though, and should be done before you crop the photo to the final size, since the "excess" real estate that is a result of the perspective adjustment may come in handy here.
 
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