My Autopano Pro forum

thanks for the reply!

So in other words, what I'm trying to do is not possible? Stitching hdr images with APP?

I could also stitch panorama's from each of the corresponding exposures, so I get 14 panorama's, and make a hdr out of that. But that will be much more work and not every image will be exactly the same so the resulting hdr will not be that good quality.

Hi,

I'm new to APP so not quite following your explanation for 100% :-) I found another thread where you explain your workflow.

I used to shoot a chrome sphere to make hdr maps for 3d rendering (http://www.aversis.be/hdri/justitiepaleis.htm for example). I'm very used to making hdr maps with this technique, but there is no stitching involved (maybe some masking in photoshop when shooting 2 angles to remove myself from the hdr).

In your workflow, if I understand correctly, you let APP stitch all your exposed shots (for example I use a 180° fisheye lens and shoot 3 angles, each with 12 exposures). So then APP stitches all the 1/1000th, all the 1/500th, etc. Then finally the 12 stitched shots are merged into a hdr image.

But the problem is that APP will never be able to stich the very short exposure shots, as these usually are completely black except some small areas where there are light sources (see attached image).

Also when making a pano from each series of exposures, there must be differences in blending or alignment between each exposure layer, which is not good for the final hdri.

The only way to make a good quality hdri is to first make hdr files from the different views, and later stitch these into a panorama. That way you only have to stitch 3 hdr's in my case since I shoot 3 angles.

Do you think hdr stitching will be a feauture someday? I can stitch my hdr's with app, but I can only save them as ldr.

Besides that, APP seems to have problems stitching only 3 views with my fisheye lens, with 4 all worked well, but when using only three the default stitch is always wrong. Stitcher unlimited from autodesk seems to stitch these perfectly without any manual work.

If anyone wants to try, I attached the images I'm trying to stitch in low res :-)

thanks,

wouter

Last edited by flipside (2008-07-24 16:10:35)

Do you think hdr stitching will be a feauture someday? I can stitch my hdr's with app, but I can only save them as ldr.

It already is a feature if you use multiband (smartblend doesnt work with hdr!), but APP2.0 will allow you to so what, as you wrote, was sometimes impossible with 1.x - instead of looking for control points even in the very dark images, with obviously will be sometimes impossible, and other times give bad results, it will FIRST create 'stacks' (stack = -2EV, 0EV, +2EV for example) and then create links between each stack, so there will be no need to first create .hdr files with other software and work on them which can be very time consuming! The final version of APP 2.0 is planned for December iirc.

1- load your 3 hdr images into APP
2- set focal to 7mm, crop circles
3- detect
4- images 1 and 3 had no link, so i found CPs manually around the chair, optimized
5- set verticals
6- turn color correction OFF. When LDR is used then all the highlights get clipped. HDR color correction is available only when you feed several different exposure of the same scene into APP, not when you feed it already HDR files.
7- Rendered using smartblend and multiband to .hdr file format.

Link to the two hdr files: http://www.divshare.com/download/5017834-cf9
Link to the .pano: http://www.divshare.com/download/5017843-ecf
These two will stay up for a week.

I then opened these two hdr files in CinePaint and adjusted exposure:

Screenshots:
1- Multiband, exposure -4
2- Multiband, exposure 0. *See footnote about why the red.
3- Multiband, exposure +5
4- Smartblend, exposure -4
5- Smartblend, exposure 0
6- Smartblend, exposure +5

*Multiband made strange visible boundaries between the images. They are not related to HDR, I reported them last year already and was told that multiband is optimized for large panoramas and might do that with small ones. I thought that meant that they are visible when I open e.g. a 20 000 x 10 000 px panorama but render it at 10%, but now I see it means even rendering at 100% as long as the real pano is small. This is definitely a bug, hopefully will be resolved in 1.9.x
See bug report http://www.autopano.net/forum/t3427-1.4 … -multiband