Pano2VR sharpness problem

[p.madaschi]

Hello
I am converting a number of panos with Pano2VR for web publishing and I see that the images generated by Pano2VR are definitely less sharp then expected.
NOTE: I will publish my photos as HTML5 with Flash fall-back, but I normally use QuickTime just for a quick check after stitching with PTGui. I use for this the PTGui embedded tool. And this is where the problem came to evidence: I had PTGui outputs definitely sharper than the Pano2VR outputs!

To check where the problem was I made a simple test.
- First of all I noticed that for Pano2VR the ouput sharpness is fairly independent from the type of output (QuickTime, Flash, HTML5), at least at my resolution level.
- I took one equirectangular image 5760x2880 pixel, sized 4.71 MB.
- I generated a Quicktime pano with Pano2VR: 90% image quality, output size 5.4 MB.
- And I did the same with PTGui: 70% quality, output size 4.03 MB.
- For both software I use the latest versions: Pano2VR 4.0, PTGui Pro 9.1.3. Standard settings, 800x600.

I don't really care about the higher size or some different perspective details, but the sharpness is definitely worse in the Pano2VR output. And it doesn't improve substantially even setting a 100% quality, a possibility by the way non acceptable for the output size.

Is it this normal? Do you have any suggestion?
Thx for your reply!
Pietro

[Hopki]

Hi,
Things that will effect quality:

Interpolation Filter, default is Mitchell which is a little soft, set to Lanczos3 or even Blakman/sinc. This is found in the programs settings/Preferences under Images (V4.x)

Cube face size, for your equirec it should be 1440px if you don't use Pi. Using Pi will increase the cube face size and give better quality, but not advised if you are going to use multi-resolution as it will be harder to work out good cube face sizes for the levels. Reducing cube face size will reduce file size but will reduce visible quality dramatically.

Image compression, this has a dramatic effect on file size without effecting visible image quality too much. Never had any reason to go above 90, there is not much if any visible difference between 90 and 100.

Hope this helps.
Regards,
Hopki

[p.madaschi]

Hi Hopki

I tried with Laczos3 and it looks promising even if the output file size is now almost the double against PTGui and it has some more artifacts.
Cube face it is 1440, that looks like a good compromise. I don't use multi-resolution at the moment. I use Pi as a conversion and not as an output factor (std setting, I didn't even know the existence of it).

Thanx for your superfast reply

Pietro


PS: Could pls update your important:
Postby Hopki » Wed Dec 21, 2011 4:34 pm
This sounds like a lot of work with all this redirecting...
To simplify it a bit more you could just have one HTML page and have that serve up the best output for the device viewing...........
CLEAR AND SIMPLE.

[Hopki]

Hi Pietro,
Since then we now have iOS6...
This changes things slightly as I now use image compression 70 for the HTML5 mobile output. I found with my old settings for the iPhone 4 and iPod Touch 4th generation:

960 => 700 => 80

This crashed mobile Safari on my iPod Touch running iOS6, agreed the iPhone 4 may work with it as it has more RAM but I don't have one of those for testing just my iPod Touch.
To stop the crashing I reduced the image compression to 70 now all works again.

This is due to the new iOS6 no longer has internal image compression so you have to add more when outputting from Pano2VR.
This does not mean the image quality is worse, it just means rather than you outputting with 80 and the old iOS added further compression, now it does not you have to add more to compensate.

For clear and simple instructions on how to set up Flash multi-resolution and the mobile outputs for HTML5 you are best going to the tutorial page on the website and looking at:

Multiresolution Basics: http://gardengnomesoftware.com/tutorial.php?movid=18_1
Multiresolution Advanced: http://gardengnomesoftware.com/tutorial.php?movid=18_2
HTML5 Export: http://gardengnomesoftware.com/tutorial.php?movid=17

Regards,
Hopki

[PORTtours]

Would you have to change the compression to 70% on all your panoramas, or would you only need to do it on the initial panorama that has the GUI connected to it?

[Hopki]

Hi,
On all mobile outputs.
Regards,
Hopki