# Spatial transformations chapter in new edition of Digital Image Processing Using MATLAB16

Posted by Steve Eddins,

In January 2006, the first month of this blog, I wrote the following: ... read more >>

# Viewing output-space coordinates for a transformed image14

Posted by Steve Eddins,

Blog reader Ram asked a question last week that I hear fairly often: When you apply a spatial transformation to an image, how can you see the x-y coordinates when you display the image? ... read more >>

# Use makehgtform for 3-D rotation8

Posted by Steve Eddins,

Developer Mike G. read my recent post about three-dimensional image rotation and suggested that users might want to use the MATLAB function makehgtform to construct the affine transform matrix. It has some convenient syntaxes. ... read more >>

Posted by Steve Eddins,

Thanks to Kimo Johnson and Perttu Ranta-aho for responding to my custom spatial transformation challenge.... read more >>

# Spatial transformations: Three-dimensional rotation72

Posted by Steve Eddins,

Blog reader Stephen N., who's been following my posts about spatial transformations, asked me last week how to rotate a three-dimensional image. ... read more >>

# Reader challenge: Custom spatial transformations10

Posted by Steve Eddins,

Were you intrigued by the custom spatial transformations I showed last week? Here's a challenge for you: Create a sample image transformation that is in some way creative, interesting, or just plain fun to look at. Use maketform('custom',...) and imtransform. Send an M-file script that demonstrates the idea to Steve.Eddins@mathworks.com.... read more >>

# Spatial transformations: Defining and applying custom transforms20

Posted by Steve Eddins,

Blog reader David A. asked me a while back about how to transform an image based on some mathematical function. For example, the online paper "Visualizing complex analytic functions using domain coloring," by Hans Lundmark, has an example of defining a spatial transformation by... read more >>

# Spatial transformations: Controlling the input and output grids with imtransform45

Posted by Steve Eddins,

The function imtransform has several optional parameters that allow you to fine-tune its behavior. Today's topic is about the parameters that let you control where the input image lives in input space, as well as the location and spacing of the... read more >>

# Spatial transformations: Handling noninvertible cases6

Posted by Steve Eddins,

I've written previously about how imtransform uses inverse mapping to compute the input-space location corresponding to each output pixel. I've also written about how imtransform uses the forward mapping to determine the location of the output image in output space. ... read more >>

# Spatial transformations: Translation confusion46

Posted by Steve Eddins,

The last time I wrote about spatial transformations, I explained that imtransform uses the function findbounds to locate the transformed image in output space. By default, imtransform computes an output image grid that is just big enough to capture the output image, wherever it is located. ... read more >>