More on perspective distortion correction
In several prior articles here (see bottom of post), I discussed perspective distortion control mostly for architectural subjects. There are many other situations where the tools for managing perspective are useful.
Let’s start with an example. Here is a quick smartphone snapshot. I grabbed this to use over on my Monday Window blog. I was after the “Next window please” sign.
Not only is there plenty of perspective distortion, but the photo is tilted. Let’ stick it into the ON1 Photo RAW editor for some quick corrections. We start in the Develop mode. In the right pane, scrolled way down to the bottom, is the Transform section. There are a number of sliders there. Here the illustration shows the use of the Rotation tool. The screen tip says “Levels the photo”.
With the Vertical slider the image will be stretched/compressed to adjust the vertical perspective. Note the tip saying “Adjusts the vertical perspective”.
Similarly, the Horizontal slider adjusts the horizontal perspective.
If you want to make all the adjustments in one operation there is the Keystone tool. When clicked it places a rectangle on the image. The tip says “Click and drag the corner elements to horizontally or vertically adjust the photo”. Indeed, it is as simple as that.
Just drag the corners to points in the photo that you want to become the corners of a rectangle. Click Apply and the correction is made.
Pretty much every post-processing editor provides such a tool.
Here is another example of using such a “Keystone” or “Perspective” tool. The painting in the cabin was selected and corrected. A few additional correction steps were done on the final image. Click image to enlarge.
See earlier articles on the subject of perspective distortion:
Perspective correction for panoramas
Perspective correction using Microsoft Image Composite Editor
.:. © 2022 Ludwig Keck
Oooh, I don’t think I have access to these tools. I’ll just have to improvise!
What do you use for post-processing, Margaret?
Just the tools available in Google photos. Don’t do a lot. A touch of straightening and cropping, maybe adjusting the light. It’s all I’m capable of, and in truth, I don’t want to do more. If a photo can’t cope with only a light touch, I junk it.
I admire your philosophy, that calls for being careful before pushing the button. Google used to have a fine tool, Picasa, for editing photos. Not all the features made it into what they now offer. If you are happy with your way and your results, cheers to you!