Comparison of a multi-res <> single-res medium sized pano

[Wim.Koornneef]

Hello Forum,

To get the differences between multi-res and single-res medium sized panoramas a bit more clear I made a comparison of both versions.
The scene is the WWII cemetery/memorial at Margraten, the Netherlands.

This is the multi-res version (200KB, tiles 14,4MB) :
http://www.dmmdh.nl/panos/PANO2VR/pano2 ... e_001.html

The same multi-res pano but now with some colored tiles in it to make the switch between the levels visible and to check the image quality of the transition, when zooming in/out and when resizing the browser window you can clearly see the switch of the 4 levels (the tiles of the smallest resolution are not colored).:
http://www.dmmdh.nl/panos/PANO2VR/pano2 ... e_002.html

This is the single-res version (7.7MB):
http://www.dmmdh.nl/panos/PANO2VR/pano2 ... e_003.html

This is a Zoomify image of the equirectangular (10336 × 5168 px), when you open the equirectangular in a separate browser window and zoom in to 100% then it is easy to compare the image quality to the panoramas:
http://www.dmmdh.nl/panos/PANO2VR/pano2 ... e_004.html

This is a screenshot of the multi-res panorama settings:
http://www.dmmdh.nl/panos/PANO2VR/pano2 ... e_005.html

The smallest resolution only serves as a workaround for the lack of a preview image, because my panos are aimed at standard monitors I didn't bother to change the Switch Bias and/or apply extra low resolution levels for use on mobile devices.

In some previous experiments I found out that with the default size jump of the levels the switch of the levels is to much visible when zooming in (unsharp<switch>sharp) and that is why I reduced the size jump.
Each tile level is now approx. 70% of the tile size of the above level (instead of 50% with the default setting), the downsize of this is a larger total file size and so a larger total download time but imo the gain in image quality makes it worth.

On my monitor with 1920x1200 px the multi-res pano shows level 4 (pink tiles) after loading, when reducing the monitor resolution to 1024x768 px then level 2 (sepia tiles) is showed.

Advantages of multi-res compared to single-res for medium sized panos:
-Much less shimmering of straight lines when zooming in/out, especially on smaller monitors shimmering can be very annoying, to see what I mean reduce the window of the normal pano and zoom in/out a bit,
-The loading time to show an initial view of the pano is shorter (depending on the multi-res settings, the download speed and the monitor resolution).

Disadvantages:
-The large number of tiles and the larger total file size can makes the total loading time a lot longer with a slow internet connection,
-For a fast upload to the web space the files needs to be zipped and after the upload the files needs to be remote unzipped (uploading unzipped files can takes a very long time).
-there is (little) more work involved.

To be honest I am not convinced if using multi-res is the best road to go for medium sized panos, for panos much larger then 10K this is the best option but for panos around 10K ?

This comparison is far from complete so I like to hear about your experiences, remarks, etc.

Wim

[Vestland]

Very interesting, thanks for doing the legwork and sharing.
I am looking forward to a more detailed tutorial from Karen at GardenGnome and a detailed user manual.

[Judy-A]

Wim, thanks so much for doing these comparisons. They're very helpful. I agree with the points you've made.

In Flash Output>Settings> Window>'FoV Mode' what is your setting? If I display your version 2 multi-res with colored tiles, and keep the browser window height constant but make the width narrower and narrower, the tile level changes until the pano is quite blurry.

I was hoping that a small initial download and tiles fed as needed would operate more smoothly than it does. In your panos and mine I'm seeing more jerkiness during panning with the multi-res panos.

Judy Arndt
1920 x 1200 display
Mac Pro Quad Core
High-speed cable internet connection

[Hopki]

I am looking forward to a more detailed tutorial from Karen at GardenGnome and a detailed user manual.

Please see here: http://gardengnomesoftware.com/wiki/Pan ... lution_Tab
This tells you what everything does.
Regards
Hopki

[Wim.Koornneef]

...In Flash Output>Settings> Window>'FoV Mode' what is your setting? ...

Hello Judy,
For FoV Mode I use "diagonal", on wide screens (f.e.1920x1200) this works better then the other options (Fov is set to 75 degree).

...I was hoping that a small initial download and tiles fed as needed would operate more smoothly than it does. In your panos and mine I'm seeing more jerkiness during panning with the multi-res panos...

On my iMac 24" I can't see any difference in panning quality between a single-res or multi-res pano and both versions runs smooth, on my MacBook Pro 15" panning is a little less smooth with multi-res but the difference is very small.
Perhaps I don't have issues because I have Flash 10.2 Preview (64bit version for OSX10.6.4) installed, if you don't have it installed I suggest you give it a try:
http://labs.adobe.com/downloads/flashplayer10.html

Success,
Wim

[hum@no.id]

Much less shimmering of straight lines when zooming in/out, especially on smaller monitors shimmering can be very annoying

- this aliasing

I always have in mind when it comes to multi-resolution ... not as an opportunity to watch the giant texture eg. Milky Way project ...

but as an opportunity to get rid of aliasing when switching from a fixed projection window mode (eg. 800x500px) to full-screen ...

as have not yet thought through good anti-aliasing filters in Flash (if high squeezed texture), which contributed to quality between-pixel interpolation when movement rendering...

A living example (mmgfx.com) - my portfolio unavailable having a multi-res tool ... used a simple switch low <-> high from two files

*It's need to remember and understand

[etegration]

I am looking forward to a more detailed tutorial from Karen at GardenGnome and a detailed user manual.

Please see here: http://gardengnomesoftware.com/wiki/Pan ... lution_Tab
This tells you what everything does.
Regards
Hopki

3.0 Beta 3 for Windows does not have the Cubic or Equi settings?

Format: Choose between Cubic or Equirect, however as flash handles cubes much better leave at default (Cubic) for optimum performance.

[Hopki]

Hi
I have just updated the Document, if your input projection is Equirectangular then the option is available.
Well Spotted
Regards
Hopki

[etegration]

Hi
I have just updated the Document, if your input projection is Equirectangular then the option is available.
Well Spotted
Regards
Hopki

Thanks Hopki, is there a general information anywhere i can read up on what exactly does Multi Resolution does?

It provides a set of multi resolution pano that can be preloaded (or not) thus panographers can simply display a single link as users view the pano, the pano will scale accordingly? Eg, when users zoom, a higher resolution cube for that particular view is loaded. Is that statement valid?

[Hopki]

Hi
Yes you are quite right, so you start of with an expectable res image, from a distance, and then as you zoom in, the magic starts
Hopki

[Wim.Koornneef]

...you start of with an expectable res image...

The start resolution is different for small and large screens and that is why I find it hard to set the proper embedded resolution.
If I embed a low resolution then only small screens will benefit from this and when I embed a larger resolution then this is fine for large screens but then small screens has to download the proper (smaller) resolution for a good display.

I know that it is possible to embed several resolutions in the flash pano but then initial download before a proper image is showed can take a long time.
To avoid a difficult and arbitrair choice what resolution to embed or not it could be an option to embed just one very low resolution that loads and shows fast, act like a preview and then leave it up to the player to load the proper start resolution.
What do you think about this workaround ?

Wim

[Hopki]

Hi Wim
Please see this bug report, Issue #87, when it is resolved what you are suggesting should be possible, just have the preview track and don't set any any resolutions for load at start up.
As a thought and not tryed.....you could make a set of very low resolution images and and make them B/W in photo editing software.
Then when making a Multi res, set this level in the levels, and then just copy in your B/W set. If the resolution is low enough, then they will only show for a brief moment as the player loads the correct res.
Hummm I may have a play, but as already said a preview track is on the way.
Hopki

[etegration]

Hi
Yes you are quite right, so you start of with an expectable res image, from a distance, and then as you zoom in, the magic starts
Hopki

thanks! you got that right! magic it is!