Prepare for the CompTIA Network+ exam by learning how to troubleshoot, configure, and manage both wired and wireless networks.

Hi everyone,

I have a bizarre image system where for an image, I get the cosines of the upper left pixel to the world coordinate system. These values are describing the direction of the columns and rows to the world coordinate system. I guess it's like trying to describe the direction of the upper edge and left edge of a plane in 3D space.

For example, I have a sample image with cosines of:

cols: 0/0/-1

rows: 0/1/0

which means the columns of the image are running down the negative z axis, and the rows are running up the positive y axis.

My question is, how could I figure out the resulting cosine direction would be if I apply an arbitrary rotation to the columns for example? If I apply a 90 degree rotation around some axis, what would the cols cosine turn out to be?

Thanks

I have a bizarre image system where for an image, I get the cosines of the upper left pixel to the world coordinate system. These values are describing the direction of the columns and rows to the world coordinate system. I guess it's like trying to describe the direction of the upper edge and left edge of a plane in 3D space.

For example, I have a sample image with cosines of:

cols: 0/0/-1

rows: 0/1/0

which means the columns of the image are running down the negative z axis, and the rows are running up the positive y axis.

My question is, how could I figure out the resulting cosine direction would be if I apply an arbitrary rotation to the columns for example? If I apply a 90 degree rotation around some axis, what would the cols cosine turn out to be?

Thanks

Experts Exchange Solution brought to you by

Enjoy your complimentary solution view.

Get this solution by purchasing an Individual license!
Start your 7-day free trial.

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trialDo you have a 2D-game and a fixed rotation-axis, like the z-axis? or is your rotation axis any axis in

3D-space, even everything else than x,y or z-axis?

If so, how do you store the rotation & its axis? Euler-Angles, Axis-Angle or Quaternions?

ike

how we can store and calculate it:

http://www.euclideanspace.com/maths/geometry/rotations/

Can you describe the image system you are reffering to?

I never saw a rotation defined just by cosines of angles.

The rotations are defined by angles. We use sin and cos of such angles to calculate the position of points around a given point (2D rotation) or around axis (3D rotation) or around an arbitrary line (also 3D rotation).

We can use matrix calculation or formulas to calculate the position of graphic entities after the rotation.

I don't remember if I had ever saw an image rotation defined by cosines in rows and collums. Which rows and cols? Is it a table? Are you sure is that an image? Which image? A bitmap? What are the entries and outputs in the system?

We need more info.

Jose

In such case, it is a matrix transformation very usual in computer graphics.

Jose

Game Programming

From novice to tech pro — start learning today.

Experts Exchange Solution brought to you by

Enjoy your complimentary solution view.

Get this solution by purchasing an Individual license!
Start your 7-day free trial.