Deep Zoom Collections explained Part 1 - coordinates and viewports

re: Deep Zoom Collections explained Part 1 - coordinates and viewports

Chris — Thu, 28 May 2009 10:58:46 GMT

Added my thoughts to my blog:

http://brainporridge.blogspot.com/

re: Deep Zoom Collections explained Part 1 - coordinates and viewports

Chris — Fri, 22 May 2009 17:26:09 GMT

This blog helped me:

http://blogs.msdn.com/jaimer/archive/2008/06/23/working-with-collections-in-deep-zoom.aspx

It says "If viewportwidth of subimage is 1 then it occupies the entire width of the msi.

If viewportwidth of the subimages is 2 then is occupies half the width of the msi."

So, in my example above, the actual width of the subimage is

Actual Width of Sub Image = 1/ViewPortWidth * MSI.ActualWidth

Then, ViewPortOrigin X and Y are factors of ActualWidth of SubImage.

So if VPO.X (or VPO.Y) = -1 it means:

-1 * 1/ViewPortWidth * MSI.ActualWidth

re: Deep Zoom Collections explained Part 1 - coordinates and viewports

Chris — Fri, 22 May 2009 17:12:16 GMT

Hmmmm:

ViewPortOrigin of the SubImage seems to be the position of the SubImage within the MultiScaleImage control not the position of the SubImage compared to the image its displaying.

for example:

If I have an MultiscaleImage of 400 * 300 and

SubImage.ViewPortOrigin = (-4,0) and

SubImage.ViewPortWidth = 5.5 then the X coordinate of the SubImage.ViewPortOrigin.X is :

-4 * 1/5.5 * 400

(SubImage.ViewPortOrigin.X * (1/SubImage.ViewPortWidth) * Multiscale.ActualWidth)

re: Deep Zoom Collections explained Part 1 - coordinates and viewports

Chris — Wed, 20 May 2009 13:54:11 GMT

Hmmm, in a collection scenario, is the ViewPortOrigin of the MultiscaleSubImage relative to the image it's displaying or the uber-image of all the images in the MultiScaleImage?

How do ViewPortOrigin.X and .Y relate to the position of the MultiscaleSubImage within the MultiScaleImage?

re: Deep Zoom Collections explained Part 1 - coordinates and viewports

Chris — Wed, 20 May 2009 13:14:21 GMT

Aha! Now that it's explained, it makes sense. I think this was the right way to go.

re: Deep Zoom Collections explained Part 1 - coordinates and viewports

William Storage — Tue, 05 May 2009 00:47:00 GMT

The terminology/nomenclature Microsoft has chosen for this is workable enough, but it seems semantically incorrect, and is at odds with common usage. A Viewport is what you look through, a window through which you see part of the picture. The entire picture might better be termed a canvas. You see part of a canvas through a viewport. The top left of the canvas, if called CanvasOrigin, would likely not confuse people by typically being negative coordinates. Any mapmaker - apparently like most Silverlight users trying out the MultiScaleImage, certainly would expect "ViewportOrigin" to refer to the coordinates of the ViewPort relative to those of the canvas - thus positive coordinates.

Deep Zoom Collections explained Part 1 - coordinates and viewports - Lutz Gerhard

DotNetShoutout — Sat, 14 Mar 2009 07:21:07 GMT

Thank you for submitting this cool story - Trackback from DotNetShoutout

Click & Solve » Deep Zoom Collections explained Part 1 - coordinates and viewports

Fri, 13 Mar 2009 09:33:48 GMT

PingBack from http://www.clickandsolve.com/?p=22350