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PostPosted: Thu Jan 08, 2009 1:57 am 
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Unless I am doing it wrong, it seems the automatic cropping (enabled in the detection settings) crops down to the point where no pixels will be lost. In other words, this is the smallest crop where all image pixels come through to the final panorama, even if some resultant panorama pixels have no information.

What I want is to have the largest crop where the final panorama has no pixels that lack information. That's not what I get with the auto cropping. What I could do is manually crop the final panorama output using other tools. But that changes the image size and I have to rescale the image from that result. Or I could manually crop in the AutopanoPro crop tool. But I cannot see, while using that tool, if I have reached the crop level that achieves my goal without going through a complete render. I'd have to do quite a few renders to get it right on the border of where it covers as much of the image as possible without getting any empty pixels.

Can someone suggest what I should do?

As described above, I want to first get the crop set to the largest size that will have no empty pixels in the resulting panorama. Then I want to render that panorama at the exact pixel height desired (often a few different sizes), so I minimize scaling artifacts in the various sizes. So I want to get that cropping just right while still in AutopanoPro before rendering.

Here is one of the resulting renders. Notice the pixels along the top and bottom edges.
http://phil.ipal.org/autopano/vance-pano/phil_vance-pano_img_1446_img_1469_24_9_5824x720_SCULS.png


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PostPosted: Thu Jan 08, 2009 3:18 am 
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You write about Autopano Pro, but it seems to me you are describing Autopano Giga. The former does what you want to do properly and automatically, the latter gives you a choice. "Edit > Settings > Panorama > Prefered extend" to make that choice. "Clamp to panorama content" is what you want. Note that this was broken in one of the alpha versions, and you shouldn't be using an alpha version for production.


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PostPosted: Thu Jan 08, 2009 5:10 am 
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DrSlony wrote:
You write about Autopano Pro, but it seems to me you are describing Autopano Giga. The former does what you want to do properly and automatically, the latter gives you a choice. "Edit > Settings > Panorama > Prefered extend" to make that choice. "Clamp to panorama content" is what you want. Note that this was broken in one of the alpha versions, and you shouldn't be using an alpha version for production.

I have Autopano Pro 1.4.2. Here is my splash screen:
http://phil.ipal.org/autopano/vance-pano/autopano-pro-splash.png

In "Edit > Settings" there are some tabs, but none are "Panorama" and none have "Preferred" or "Preferred extend" as a choice. I do not see "Clamp to panorama content" as an option. I do not find these words in the documentation.


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PostPosted: Thu Jan 08, 2009 7:35 am 
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Phil Howard wrote:
...Then I want to render that panorama at the exact pixel height desired (often a few different sizes), so I minimize scaling artifacts in the various sizes.

I agree that the auto crop is often a bit too strong. To get the maximum area in the picture, I use the manual crop, zooming to 200%. The lines drawing the cropping box are not thin enough to be always accurate.
When you need different size of the panorama, I understand that you render it several times at the desired sizes. If you are concerned by scaling artifact, I suggest you read this post by DrSlony:
http://www.autopano.net/forum/p21382-2008-02-28-16-56-04#p21382
I prefer to render one time at the maximum size then I do different down scaling with photo editor.

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PostPosted: Thu Jan 08, 2009 4:43 pm 
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marco-pano wrote:
Phil Howard wrote:
...Then I want to render that panorama at the exact pixel height desired (often a few different sizes), so I minimize scaling artifacts in the various sizes.

I agree that the auto crop is often a bit too strong. To get the maximum area in the picture, I use the manual crop, zooming to 200%. The lines drawing the cropping box are not thin enough to be always accurate.
When you need different size of the panorama, I understand that you render it several times at the desired sizes. If you are concerned by scaling artifact, I suggest you read this post by DrSlony:
http://www.autopano.net/forum/p21382-2008-02-28-16-56-04#p21382
I prefer to render one time at the maximum size then I do different down scaling with photo editor.

Maybe Photoshop does better than GIMP on the scaling. I've had some bad results. Also, I'm on Linux so I can't run PS so easily. Anyone know of a PPM plugin for better scaling?


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PostPosted: Thu Jan 08, 2009 5:56 pm 
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Gimp seems to add little jaggies when scaling down images a lot but they are visible only on cases like a wire running against a sky background... sometimes it does eliminates the need for sharpening after scaling, but I wish they would implement more scaling algorithms, there are plenty of them around and I don't think this is something difficult to do.

When you wrote that you had some bad results with Gimp, can you show examples of what you mean? Is it like what I described?

The best scaling algorithm/program I used was in a batch processor called Phatch, the scaling method is called "antialiased" but I heard the proper name for it is sync. So if Gimp implemented sync for downscaling (I'm talking about downscaling the whole time here, not upscaling) then I'd be happy and my life would be sharper and less jagged ;]


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PostPosted: Thu Jan 08, 2009 7:46 pm 
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DrSlony wrote:
When you wrote that you had some bad results with Gimp, can you show examples of what you mean? Is it like what I described?

I didn't save any. It was a while back on a previous computer system (so maybe 2 to 4 years).


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PostPosted: Fri Jan 09, 2009 12:55 am 
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It seems if I make no effort to do cropping at all (e.g. do not click on the crop button), then it comes out apparently as desired.


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