Fixing keystoning

Discussion in 'Nikon' started by rick waller, Jul 6, 2006.

  1. Need a little help here please. Took an image of a building for my son to use
    in a brochure. Because of the cramped positioning, I was unable to shoot with
    a level camera and the image tilts back and inward.

    I tried crop fix and other perspective fixes in PS, but was unable
    to "straighten" the vertical lines on the outer edges of the building. Any
    special tricks to rectify this severe keystoning?

    Anyone good with the Free Transform tool?
     
  2. Eric, Upgrade your PS to PS9 (PS-CS2, Check adobe's site, about $170).
     
  3. duplicate layer> edit> transform> perspective (or skew, or distort or whatever you like best). There are other methods that may work better... t
     
  4. Eric,

    Here's a technique which works with older Photoshops such as PS 5.

    Open your image and zoom out one step so there is some extra canvas around the image.

    Using the rectangular marquee, select the entire image.

    Click Edit-Transform-Distort

    Notice the small handles in the corners and middle of the sides of the image. Pull the left corner up and out, then the right corner up and out to the shape you desire. You can adjust and readjust the image to suit then click enter to do the transformation. You can use the handles in the middle of the edges of the image to stretch left, right, up or down also.
     
  5. Hi Tom !
     
  6. You can use the free-transform tool, especially while holding the "shift" key, but there may be an easier way. First rotate the picture so that the center line is perfectly vertical. Then "select all" and use the perspective transform symmetrically - stretch the top and squeeze the bottom equally. That way you preserve the aspect ratio of the original subject. Finally, crop away the chunks that "squeezing" removes.

    The key is to normalize the centerline.
     
  7. One other thing...it helps to create ruler lines to line up the verticals.
     
  8. The easiest way to rotate the image so that it is level is to zoom into an area near the center of the image which has a straight line or edge that is supposed to be level. It can be a horizontal or vertical edge near the center of the image.

    Using the measuring tool, trace a segment of that edge or line.

    Click image-rotate canvas- arbitrary and the image will autimatically rotate the correct number of degrees to place that line level either horizontally or vertically. No need to use a grid or guess the number of degrees needed.
     
  9. Thank you all. You guys are great. Seems to have done the trick. Still playing aroung with fine tuning the image, but I have the concept down pat now.

    Again - many thanks.
     

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