Pat's dashboard

Pat replied on November 03, 2009 23:03 to the question "How Do I Set the Initial Viewport Zoom?" in OpenZoom:

The answer is that I was loading the image descriptor XML file from the server and this is an asynchronous process... So the image component and viewport setup were on two different threads (I forget exactly what was happening - I had drawn a sequence diagram at one point but lost it. I think one track was started when the component's children were created and the other was explicitly an async url load). The result was that it was difficult to know when things were stable because sometimes you'd get a viewport setup event before and after the real image descriptor was set.

So I just changed to a static (hard coded) image descriptor in the MXML and it was fine... not as flexible, but fine.

Pat reported a problem in OpenZoom on October 09, 2009 04:07:

Changing MultiScaleImage Source Bug

When I change the source on my multiscale image it does what I expect and loads the new tiles, however it seems to mess up the controllers... Specifically, I lose all control with the mouse except for single clicking to zoom in. What is really weird is that if I take focus away from the browser (Firefox) and then bring it back up it starts working again.

I'm doing this on a Mac, so I'm guessing that it has something to do with the hacks required to get mouse zooming working... But what would that have to do with changing the source?

Should I be doing something else to update the source on a multiscale image?

thanks,
Pat

Pat replied on October 07, 2009 03:15 to the question "How Do I Add a Background to MultiScaleImage?" in OpenZoom:

I haven't dug that far into the container yet. Are there any docs or examples that would help me understand how to use those components?

thanks,
Pat

Pat replied on October 07, 2009 02:54 to the question "How Do I Add a Background to MultiScaleImage?" in OpenZoom:

Thanks. I'll have to see if I can get a standalone example together. For now I think I'm going to resort to rendering the background into the image tiles.

You can load an SVG as a Sprite like this:

[Embed(source="Some.svg")]
[Bindable] public var earth:Class;
...
var sprite:Sprite = new earth() as Sprite;

Now, I already add an empty Sprite on top of the multiscale image in order to draw onto it and that works fine. I understand how to convert between the three coordinate spaces (my image, the scene, and local) and all is well. However when I try to add the SVG sprite as a background things get wonky. I try setting the sprite.width and sprite.height to something reasonable but it doesn't work... the whole scene gets skewed. If the sprite is much smaller than the scene it sort of appears to work, but as it approaches the size of the scene the multiscale image shrinks and the sprite appears too large and offset... I really don't know what it's doing.

I have also tried setting the sprite's scaleX and scaleY instead of width and height, but to the same effect. I also tried adding the SVG to a Canvas and then adding that to the multiscale image, but that doesn't appear at all for some reason.

I read in one of your posts that UIComponents don't work as renderers... Maybe this is stemming from that?

thanks,
Pat

Pat asked a question in OpenZoom on October 06, 2009 19:35:

How Do I Add a Background to MultiScaleImage?

I'm pulling my hair out trying to simply add an SVG or SWF background to my deep zoom image. I naively assumed I could just set the image's width and height to the scene width and height all would be well.. but that doesn't work. In fact simply adding them seems to change the scene dimensions... e.g. if I add my image at scene width and height (which are different by the way for some reason) the entire view becomes squashed and scaled. I thought I might be exceeding some max dimension so I tried adding it at half the width and height of the scene and it still distorts the scene somehow.

I could describe this in more detail but I'm not sure it would help...

Should I just give up on SVG an background or is this possible?

thanks,
Pat

Pat reported a problem in OpenZoom on October 04, 2009 04:02:

Removing Controllers Bug

I find that sometimes assigning a new set of controllers to a multiscale image does not properly remove the existing controllers. Specifically, the first time I modify the set of controllers it seems to work, but thereafter the controllers linger and it's impossible to get them to stop.

As a temporary workaround I am looping through the controllers and setting their views to null... this seems to work as a quick hack.

Pat replied on October 03, 2009 13:33 to the question "Why Do I See Rendering Artifacts With Transparent Images in OpenZoom?" in OpenZoom:

Aaarg! (pulling hair out). I see that you have moved the codebase to github. I have been diligently watching the google code svn repository for any changes.

And yes, version 0.4.2.1 appears to fix the problem. (Curious as to how you addressed it).

I guess I should have tracked your blog... but now that I see you're leaving! Double arg! :)

Well, you've done a fantastic job on this and I hope you'll return when the time is appropriate. We all appreciate your effort on this.

Pat

Pat replied on October 03, 2009 12:57 to the question "Why Do I See Rendering Artifacts With Transparent Images in OpenZoom?" in OpenZoom:

Daniel,

I'm actually using the trunk from SVN.
Should I be using a branch?

Pat

Pat replied on October 02, 2009 17:44 to the question "Why Do I See Rendering Artifacts With Transparent Images in OpenZoom?" in OpenZoom:

I've dug through the source a bit and as near as I can tell this is just a side effect of the way that openzoom works... It seems that in smooth rendering mode it loads all of the tile layers up to the current layer into the display list... So if I'm understanding correctly, the scaled versions of my tile images going all the way down to 1 pixel are now being scaled up to the full view size and layered on top of one another. So any artifacts in the transparent areas (produced by scaling, anti-aliasing or whatever) are showing through in a kind of halo...

I guess my question is - how does everyone else deal with this? Is anyone using transparent images in tiles in this way?

Pat

Pat asked a question in OpenZoom on September 30, 2009 17:12:

Why Do I See Rendering Artifacts With Transparent Images in OpenZoom?

When I try to display PNG tiles with a transparent background I'm getting weird artifacts (halos) around the images. I've checked that these are not in my tiled images of course, they seem to be getting generated by the MultiScaleImage. I'm going to try to attach an example to this post.

I am just guessing, but I wonder if it could have something to do with that splash image that it puts up from the very low resolution tile prior to the rendering. What I mean is, I've noticed that before rendering the full multiscale image OpenZoom seems to put up a highly scaled low resolution version of one of the images first... I'd (independent of this issue) really like to turn that off.. but now I'm also wondering if that is somehow leaving something composited behind.

To be clear, the artifacts are persistent and they scale with the image as I zoom and drag around.

Any suggestions would be appreciated. Thanks.

Pat replied on August 29, 2009 18:24 to the question "Is Multi-domain Parallel Tile Loading Possible with Deep Zoom File Format?" in OpenZoom:

If I just use a trivial naming convention like prefix 1. 2. 3... to the domain, how hard should it be for me to find the code where you do the parallel loading and get that to work with the deep zoom descriptor? Is it just a limitation of the descriptor or does it go deeper?

thanks,
Pat

Pat asked a question in OpenZoom on August 28, 2009 22:55:

Is Multi-domain Parallel Tile Loading Possible with Deep Zoom File Format?

I noticed back when I was using the open zoom format that you had an option to allow tile loading from multiple domains simultaneously in order to increase parallelism in the browser. After reporting some issues you suggested that I switch to the deep zoom format a while back. I'm wondering if there is any way to accomplish the same with that format.

thanks,
Pat

Pat asked a question in OpenZoom on August 28, 2009 03:32:

How Do I Set the Initial Viewport Zoom?

Can you tell me how to set the initial zoom of a multiscale image correctly? The zoom property of the mxml appears to set the component zoom, not the viewport zoom.

I know how to drive the viewport to a zoom procedurally after the image is constructed; however I'd like the first image the user sees to be at my prescribed zoom level. If I use zoomTo() after the app setup is complete I get the big blurry image for a few frames and then the new scale pops up.

I'm guessing there is an option somewhere that i'm missing.

thanks,
Pat

Pat replied on August 28, 2009 03:28 to the question "How Do I Calculate the Maximum Zoom?" in OpenZoom:

I haven't read the rest of the thread in detail, but I just went through this calculation. I think this will give you the zoom level to make your image 1 to 1 on the screen:

private function get1to1Zoom():Number
{
var descriptor:IMultiScaleImageDescriptor = getGridImageDescriptor();
if ( grid.viewport.viewportWidth < grid.viewport.viewportHeight )
{
return descriptor.width / grid.viewport.viewportWidth;
} else {
return descriptor.height / grid.viewport.viewportHeight;
}
}

Note that the viewport has to be set up before this is useful. i.e. in applicationComplete().

Pat replied on August 12, 2009 19:24 to the question "How Do I Convert Mouse Click Coordinates into Image Coordinates?" in OpenZoom:

I'm looking to have it move and scale with the scene. Thanks for the pointer. I looked at the Z-visualization as an example but when I add a sprite as a child and draw on it it does not seem to appear over the deep zoom image that my container has loaded. Should the sprite work in that case where the container has an image loaded? Or is it intended only for an interactively drawn situation?

Maybe I need to add it in a certain order or after the image has loaded at some point? Right now I'm just following the example and doing it in the applicationComplete handler.

thanks again,
Pat

Pat replied on August 11, 2009 19:53 to the question "How Do I Convert Mouse Click Coordinates into Image Coordinates?" in OpenZoom:

This looks right, but I'm not sure if it's correct:

var pt:Point = image.localToScene(
new Point(image.mouseX, image.mouseY) );
var x:Number = pt.x / image.sceneWidth * actualImageSize;
var y:Number = pt.y / image.sceneHeight * actualImageSize;

And that assumes that I know the actual image size (as specified in the deep zoom file). Is there some property that will tell me that?

Is the above the most accurate way to calculate the real image coordinates of a mouse click on the multiscale image?

thanks,
Pat

Pat asked a question in OpenZoom on August 11, 2009 18:27:

How Do I Convert Mouse Click Coordinates into Image Coordinates?

I am rendering a deep zoom MultiScaleImage and I'd like to determine the image coordinates where the user clicks.

Can someone tell me specifically how I can convert the mouse click coordinates into the true image coordinates?

I'm looking at localX and localY from the mouse click but they do not make sense to me... Nor does the result of localToScene(), etc.

thanks,
Pat

Pat replied on June 29, 2009 17:42 to the question "Why Doesn't my Image Show Up In MultiScaleImage?" in OpenZoom:

Ok. I had just chosen the Deep Zoom format because it seemed clear and easy to generate procedurally.

So, using the viewport property I can get the multiscale image to zoom out? (choose the appropriate layer) or will that just scale the current view in a flash-y way?

thanks,
Pat

Pat replied on June 24, 2009 04:03 to the question "Why Doesn't my Image Show Up In MultiScaleImage?" in OpenZoom:

So, I grabbed the latest from SVN and built it with the SDK (despite a bug in the build file regarding the manifest.xml location) so that I could have the source available for debugging...

Low and behold simply using the freshly built libs it works now... as I would have expected all along.

So there is definitely something wrong with the sample build.

Now the only issue that I have is that I can't seem to control the default zoom properly... I set the zoom on the image and the first time it loads it always comes up full... however if I reload it it usually comes up at the specified zoom.

Pat replied on June 22, 2009 23:33 to the question "Why Doesn't my Image Show Up In MultiScaleImage?" in OpenZoom:

Let me try a different angle :)

Does anyone have an example that uses the openzoom format to do a simple zoom in a few levels deep? The only one that I can find online is the "me" example and it a) has elements that i don't understand and that are not documented that I see - specifically the "source" full scale images and b) does a weird zoom-out thing instead of zoom in... which makes it hard for me to do a direct comparison with my setup... Yes, I know, it's just levels, but ...

I believe I understand what it is doing, however my example simple displays a blank screen and I have no idea why.

thanks,
Pat