Here’s a simple method to accurately straighten images using the Measure Tool.
The below image was taken with a slight angle and will require some adjustment.
We could simple Ctrl+T and manually transform the image into place, but often without accuracy, and is pure hit and miss.
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Instead, select the ‘Measure Tool (I)’ from the Toolbar as I have captured below.
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Next, click and drag along an area of your image that best represents an arbitrary focal point for transformation.
Since I know this image was not taken on a hill, I used the curb of the road as my focal point.
Note: Notice up on the Options Bar the ‘A’ (Angle) at which my measurement has been drawn.
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Next go ‘Image/Rotate Canvas/Arbitrary’ menu command as I have captured below.
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You will be propted to choose a CW (Clockwise) CCW (Counter Clockwise), and the ‘A’ (Angle) integer we saw earlier on the Options Bar will be the arbitrary value. Keep it at CW and click OK.
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The image will be be straigened to the arbitrary integer as drawn by the ‘Measure Tool (I)’.
Apply further straightening measure if necessary and then apply a Crop transformation to eliminate unwanted areas of the image.
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