Using Adobe Photoshop Perspective Warp To Get Top View On Large Chalk Drawings
And now, my own little behind-the-scenes feature for yesterday's post about Pasadena Chalk Festival 2019. When organizing my photos from the event, I realized it might be difficult to see progression from one picture to the next due to changing viewing angles. When I revisit a specific piece, I could never take another picture from the same perspective. Most of the time it was due to someone else in the crowd blocking my view, though occasionally it's the artist himself/herself.
Since these chalk drawings were large, we could only take pictures from an oblique angle making the problem even worse. So for yesterday's post I decided it was time to learn the Perspective Warp tool in Adobe Photoshop and present a consistent view across shots. There are plenty of tutorials on how to do this online, and now we have one more:
Step 1: Load original image
Optional: Use "Image Rotation..." under "Image" menu to rotate it most closely approximating the final orientation. In this specific example, the camera was held in landscape mode (see top) and so the image had to be rotated 90 degrees counterclockwise. Photoshop doesn't particular care about orientation of your subject, but it's easier for our human brains to pick up problems as we go when it's properly oriented.
Step 2: Under the "Edit" menu, select "Perspective Warp"
Step 3: Enter Layout Mode
Once "Perspective War" has been selected, we should automatically enter layout mode. If not, explicit select "Layout" from the top toolbar.
Step 4: Create Plane
Draw and create a single rectangle. There are provisions for multiple planes in layout mode, but we only need one to correspond to the chalk drawing.
Step 5: Adjust Plane Corners
Drag corners of perspective plane to match intended surface. Most chalk drawings are conveniently rectangles and have distinct corners we could use for the task.
Step 6: Enter Warp Mode
Once the trapezoid is representative of the rectangle we want in the final image, click "Warp" on the top toolbar.
Step 7: Warp to desired rectangle
Drag the corners again, this time back into a rectangle in the shape we want. Photoshop has provided tools to help align edges to vertical and horizontal. (See tools to the right of "Warp") But establishing the proper aspect ratio is up to the operator.
Step 8: Perspective Warp Complete
Once perspective correction is done, click the checkbox (far right of top toolbar) to complete the process. At this point we have a good rectangle of chalk art, but the image around it is a distorted trapezoid. Use standard crop tool to trim excess and obtain the desired rectangular chalk art from its center.
