For this tutorial, Iâ€™ve used Adobe Photoshop CS3, and Adobe Photoshop Elements 5. While the Photoshop rotation technique is unique to that program, the Elements technique is very similar to methods used in Corel Paint Shop Pro, Ulead PhotoImpact and several other popular image editing programs.
There are many reasons why you might want to rotate a picture. If youâ€™ve taken a photo in vertical portrait format (the camera held sideways) then you may need to rotate the picture afterwards to view it at the correct angle. In most cases this will be a simple 90-degree flip which is usually a single simple menu option, and in some cases may be carried out automatically by the camera.
A common reason for rotating an image is to correct a sloping horizon or tilting vertical. It is very difficult to hold even a professional SLR camera precisely horizontal, and with tiny pocket compacts the problem is even worse. As a result many holiday snaps will feature the sea with a slope steep enough to ski on, or a Leaning Tower of Paris.
Take this photo for example. Itâ€™s a fairly typical example of a potentially good photo slightly marred by a distractingly tilted horizon. If we can level it up the picture will look much better.
Correcting accidental tilts like is relatively easy, and most popular consumer editing software has some sort of feature to quickly re-set tilted horizons or bent buildings back to horizontal or vertical. As usual Iâ€™m demonstrating this with Photoshop Elements 5.0, but youâ€™ll find similar options in most popular programs such as Paint Shop Pro or PhotoImpact.
In the tool palette, about half-way down, youâ€™ll find the Straighten tool. Youâ€™ll find it in much the same place in Paint Shop Pro, while in PhotoImpact it is one of the functions of the Warp tool. Select the tool, and youâ€™ll notice a couple of options at the top of the screen. One is Rotate All Layers, which should be checked on by default, and the other is a drop-down menu with some cropping options. If you just want to quickly rotate a snapshot then select Crop to Remove Background, but if you think you may want to fine-tune the composition after rotating then select Grow or Shrink Canvas to Fit.
To use the Straighten tool, simply click and drag anywhere on the horizon line, drawing out a line along the horizon. As soon as you release the mouse button, the picture will be instantly rotated to make this line horizontal. The Straighten tool in Photoshop Elements only works with horizontal lines, but itâ€™s worth noting that the Straighten tool in both Paint Shop Pro and PhotoImpact works slightly differently. It places a moveable line on the image which you can reposition to follow any line in the picture which should be either horizontal or vertical, such as the edge of a building. Ones itâ€™s in position, just double click to straighten the image. If the line is closer to vertical, it will move to vertical; if it is closer to horizontal, it will move to horizontal.