If only rotating tires were really this easy! After graduate school, I drove east for my post-doc at Woods Hole Oceanographic Institution. In late winter, I noticed that my tires still had red dust on them from visiting national parks in Utah. So I took a picture and later realized that my tire wasn't oriented for easily reading the make of the car.
Some Simple Image Processing
Today I am going to use some features from Image Processing Toolbox. You might also benefit from reading Steve's blog on image processing.
Read an Image
Here's a gray-scale image of my tire photo.
I = imread('tire.tif'); whos I colormap(gray(256)) image(I), axis image, axis off
Name Size Bytes Class Attributes I 205x232 47560 uint8
Crop the Image
Next I want to select the hub to look at it more closely. I happen to know that region I want to look at, having already used imcrop interactively earlier to isolate the central portion.
rect = [90 74 41 41] midI = imcrop(I,rect); image(midI), axis image, axis off
rect = 90 74 41 41
Resize the Image
Next, I want to resize the image so I can see details better.
midI5 = imresize(midI,5); imshow(midI5)
Rotate the Image
Looking at the function imrotate, I see I specify the rotation I want in a counterclockwise sense. Eyeballing the angle, I choose 135 degrees.
midI5r = imrotate(midI5, 135); imshow(midI5r)
Check the Tire Rotation
Here's the rotated tire. Now you know what kind of car I drove across the country some years ago.
Ir = imrotate(I,135); imshow(Ir)
Like today's blog, I occasionally enjoy trying out products in addition to MATLAB, in part so I can learn more about a particular domain or discipline. Have you used MATLAB or other MathWorks tools to teach yourself about some new technology or application? If so, please let me know here.
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