What should you do if you find that the photo taken on your mobile phone is a big one?
The following article will help you.
A friend asked me what to do if a square object was taken as a trapezoid.
This is a common problem.
We all know that normal lenses, especially wide-angle lenses, will converge in perspective when the lens is not horizontal, slightly up or down, that is, the parallel side of the building will tilt upwards, generate the effect of aggregation.
Professional photographers generally use Shift-axis lenses or technical cameras to solve this problem. But that stuff is very expensive, and it is not the same as our normal users. However, there is a way in Photoshop to correct this problem to a certain extent, that is, to use the perspective correction function in the cropping tool.
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First, it is an indoor figure. This deformation is obvious. Originally, the two sides of the shelf should be parallel lines, and now it will converge downward.
Selected crop tool
Note that there is an option of "Perspective" above and you can select it.
Then select the crop range. Note: When you move the mouse to the four corners of the selected range, you will find that the cursor does not change to a normal Double arrow, but to a gray triangle, at this time, you can modify the shape of the selected area.
It is easy to understand that to make the final film into a horizontal and vertical image, we need to parallel the edge of the constituency with the line you want to straighten.
Double-click. Have you seen it? The Perspective on both sides of the bookshelf is much better than just now.
This is the basic method. I will give you another example.
This kind of house skew occurs when the horizon is not in the center of the picture. However, it is impossible for us to make the horizon pass through the picture in every photo. How can we make a picture? Therefore, you need to adjust the perspective at this time.
We adjusted the left side based on the vertical line of the house next to the tower crane.
Adjust the right side in the vertical direction of the red building.
Effect after adjustment.
Remember, this adjustment is always lossy. First, you lose part of the picture (for example, P2 tower cranes and buildings). Second, the picture will be changed and become fat or thin, in addition, barrel distortion and other lens problems will become more prominent. Finally, after all, Photoshop is a software that obtains results through computation. All these perspective adjustments we make are obtained through computation and interpolation, after adjustment, the image will lose a lot of image quality. Therefore, the adjustment range should not be too large. Do not completely require Horizontal and vertical. After all, this is not in line with the real world shape.
Photo trapezoid correction
