Hi Greg, Thanks for the clarification regarding -s factor. I was getting some green colored hdr images previously but now they are coming properly. It may be due to the camera response function; now it seems to work fine with my camera. Thank you for the help.
Regards, Sneha Jain M.S by Research in IT in Building Science, Center for IT in Building Science Lab, International Institute of Information Technology, Hyderabad-500032, India On Thu, Jul 13, 2017 at 11:03 PM, Gregory J. Ward <[email protected]> wrote: > Hi Sneha, > > Glad that worked for you. I'll include it in the package on my website > for future downloaders. > > The -s factor doesn't have to be exact. It just has to have the correct > relative relation between captures. If you capture your images in the > usual 1-EV separation, you might use for example: > > img1.jpg 1/60th second > img2.jpg 1/125th second > img3.jpg 1/250th second > > hdrgen -s 1 img1.jpg -s 2.0 img2.jpg -s 4.0 img3.jpg > > In other words, you want the pixels times the multipliers to roughly equal > each other (within the limits of exposure range). If you happen to know > what the absolute level of some image is, you can use that. Here is an > approximate formula for the -s factor based on ISO, f-stop, and exposure > time: > > s2nits = 87*f_stop^2/(exp_time*ISO) > > Cheers, > -Greg > > *From: *Sneha Jain <[email protected]> > > *Date: *July 13, 2017 5:36:55 AM PDT > > > Hi Greg, > > Thank you so much for providing this version. I am glad to inform you that > this version is working with Linux 64-bit. Though I am struggling to > understand the -s stonits factor for each LDR image that I need to specify > for getting an HDR image. I am connected to a fish-eye lens all-sky camera > and unable to get this factor automatically. If you could suggest me on how > to get this; it would be really great. > > Thank you. > > Regards, > > Sneha Jain > On Wed, Jul 12, 2017 at 7:40 PM, Gregory J. Ward <[email protected]> > wrote: > >> Hi Sneha, >> >> Try this version and tell me if it's any better. Building under Linux is >> painful because of the required libraries (OpenEXR in particular). >> >> Cheers, >> -Greg >> >> P.S. I "cleared" your post to the HDRI mailing list, but you need to >> subscribe to the list using the address you post with in order for this to >> be unnecessary. >> >> >> >> *From: *Sneha Jain <[email protected]> >> >> *Subject: *Request for hdrgen's updated version for Linux 64-bit system >> >> *Date: *July 12, 2017 3:34:08 AM PDT >> >> *To: *[email protected] >> >> >> Dear Mr. Gregory Ward, >> >> I am Sneha Jain pursuing MS in Building Science from International >> Institute of Information Technology Hyderabad, India. I have gone through >> this previous Radiance thread >> <https://radiance-online.org/pipermail/hdri/2012-August/000429.html> >> about running hdrgen on Linux. I have tried using hdrgen from anyhere.com >> but then I came to know that it only works on 32-bit system. Please let >> me know if there is any latest version of hdrgen available for 64-bit >> Ubuntu and if you can send me the same. >> >> Thank you. >> >> >> Regards, >> >> Sneha Jain >> >> >> >
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