Hello Greg: Thank you very much for your answer. I will explore more about fisheye_corr.cal.
Hello Alstan: Thank you for your explanation. I got this information from the manufacturer, but based on the paper you sent, I made a mistake. Thank you for saving my time and effort. Zhe On Thu, Jan 26, 2017 at 10:11 AM, <[email protected]> wrote: > Send HDRI mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.radiance-online.org/mailman/listinfo/hdri > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of HDRI digest..." > > > Today's Topics: > > 1. Convert equisolidangular to equiangular projection (Zhe Kong) > 2. Re: Convert equisolidangular to equiangular projection > (Gregory J. Ward) > 3. Re: Convert equisolidangular to equiangular projection > (J. Alstan Jakubiec) > 4. Re: Convert equisolidangular to equiangular projection > (Claus Br?ndgaard Madsen) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 25 Jan 2017 15:15:49 -0600 > From: Zhe Kong <[email protected]> > To: [email protected] > Subject: [HDRI] Convert equisolidangular to equiangular projection > Message-ID: > <CAEV5NycbY6hLjbPSmVb1H5pj_PW-Y4rNMjzrY4KJ2sLXkbV_wA@mail. > gmail.com> > Content-Type: text/plain; charset="utf-8" > > Dear list: > I am trying to compare HDR images and simulated luminance maps. Since I use > SIGMA 8mm 1:3.5 for Canon, I need to convert equisolid-angular to > equiangular project. I see very useful information from the post below: > > https://www.radiance-online.org:447/pipermail/radiance- > general/2015-August/011184.html > > However, I still have some questions need to figure out. > 1) pinterp does not include equisolid-angular projection, so a equation > needs to be applied to the function. Greg mentioned this simple expression, > sin(theta)/theta, but I am still confused. Could anyone offer me the > command? > > 2) The post discussed the steps of processing HDR images. If I get it > right, the steps following "adjust exposure" are vignetting correction, > adding view information, converting project from equisolidangular to > equiangular, then calibrating the image. I use a GOSSEN Starlite 2 to > record the luminance value on a grey card for calibration. My question is, > should I calibrate the image before or after converting fisheye projection? > > Any suggestions or explanation would be appreciated. > > Zhe > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://www.radiance-online.org/pipermail/hdri/ > attachments/20170125/6009a4a8/attachment-0001.html> > > ------------------------------ > > Message: 2 > Date: Wed, 25 Jan 2017 16:48:55 -0800 > From: "Gregory J. Ward" <[email protected]> > To: High Dynamic Range Imaging <[email protected]> > Subject: Re: [HDRI] Convert equisolidangular to equiangular projection > Message-ID: <[email protected]> > Content-Type: text/plain; charset=iso-8859-1 > > Hi Zhe, > > You should be able to apply the fisheye_corr.cal file I gave you earlier > to correct the distortion and make it an angular fisheye image that pinterp > works with. (Why you need pinterp, I am not sure.) The command is as > suggested in the fisheye_corr.cal file itself: > > pcomb -f fisheye_corr.cal -o fisheye.hdr \ > | getinfo -a "VIEW= -vta -vh 180 -vv 180" \ > > corrected.hdr > > This will also crop the area outside of 180? to black, assuming that is > what you want. It assumes that you have already cropped the image to a > minimum square area. You should apply vignetting correction and absolute > calibration first. > > Cheers, > -Greg > > > From: Zhe Kong <[email protected]> > > Date: January 25, 2017 1:15:49 PM PST > > > > Dear list: > > I am trying to compare HDR images and simulated luminance maps. Since I > use SIGMA 8mm 1:3.5 for Canon, I need to convert equisolid-angular to > equiangular project. I see very useful information from the post below: > > > > https://www.radiance-online.org:447/pipermail/radiance- > general/2015-August/011184.html > > > > However, I still have some questions need to figure out. > > 1) pinterp does not include equisolid-angular projection, so a equation > needs to be applied to the function. Greg mentioned this simple expression, > sin(theta)/theta, but I am still confused. Could anyone offer me the > command? > > > > 2) The post discussed the steps of processing HDR images. If I get it > right, the steps following "adjust exposure" are vignetting correction, > adding view information, converting project from equisolidangular to > equiangular, then calibrating the image. I use a GOSSEN Starlite 2 to > record the luminance value on a grey card for calibration. My question is, > should I calibrate the image before or after converting fisheye projection? > > > > Any suggestions or explanation would be appreciated. > > Zhe > > > > > > ------------------------------ > > Message: 3 > Date: Thu, 26 Jan 2017 13:57:36 +0800 > From: "J. Alstan Jakubiec" <[email protected]> > To: [email protected] > Subject: Re: [HDRI] Convert equisolidangular to equiangular projection > Message-ID: <[email protected]> > Content-Type: text/plain; charset="windows-1252"; Format="flowed" > > Hi Zhe, > > As far as I am aware, the Sigma 8mm f/3.5 is an equi-angular (-vta) > lens, and the Sigma 4.5mm f/2.8 is an equi-solid angle (-???) lens. I am > having trouble finding a source from Sigma right now, but Cauwerts, > Bodart and Deneyer's paper > <http://www.tandfonline.com/doi/abs/10.1582/LEUKOS.2012.08.03.002> says > so. > > That said, if you do end up with an equi-solidangle image, I have a > python script that converts equi-solid angle to equi-angle for each > source jpeg while maintaining the EXIF data. I used this to convert > equi-solidangle images from my Canon 8-15mm fisheye lenses. > > Best, > Alstan > > On 1/26/2017 8:48 AM, Gregory J. Ward wrote: > > Hi Zhe, > > > > You should be able to apply the fisheye_corr.cal file I gave you earlier > to correct the distortion and make it an angular fisheye image that pinterp > works with. (Why you need pinterp, I am not sure.) The command is as > suggested in the fisheye_corr.cal file itself: > > > > pcomb -f fisheye_corr.cal -o fisheye.hdr \ > > | getinfo -a "VIEW= -vta -vh 180 -vv 180" \ > > > corrected.hdr > > > > This will also crop the area outside of 180? to black, assuming that is > what you want. It assumes that you have already cropped the image to a > minimum square area. You should apply vignetting correction and absolute > calibration first. > > > > Cheers, > > -Greg > > > >> From: Zhe Kong <[email protected]> > >> Date: January 25, 2017 1:15:49 PM PST > >> > >> Dear list: > >> I am trying to compare HDR images and simulated luminance maps. Since I > use SIGMA 8mm 1:3.5 for Canon, I need to convert equisolid-angular to > equiangular project. I see very useful information from the post below: > >> > >> https://www.radiance-online.org:447/pipermail/radiance- > general/2015-August/011184.html > >> > >> However, I still have some questions need to figure out. > >> 1) pinterp does not include equisolid-angular projection, so a equation > needs to be applied to the function. Greg mentioned this simple expression, > sin(theta)/theta, but I am still confused. Could anyone offer me the > command? > >> > >> 2) The post discussed the steps of processing HDR images. If I get it > right, the steps following "adjust exposure" are vignetting correction, > adding view information, converting project from equisolidangular to > equiangular, then calibrating the image. I use a GOSSEN Starlite 2 to > record the luminance value on a grey card for calibration. My question is, > should I calibrate the image before or after converting fisheye projection? > >> > >> Any suggestions or explanation would be appreciated. > >> Zhe > >> > > _______________________________________________ > > HDRI mailing list > > [email protected] > > http://www.radiance-online.org/mailman/listinfo/hdri > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://www.radiance-online.org/pipermail/hdri/ > attachments/20170126/2e646a95/attachment-0001.html> > > ------------------------------ > > Message: 4 > Date: Thu, 26 Jan 2017 10:17:01 +0000 > From: Claus Br?ndgaard Madsen <[email protected]> > To: High Dynamic Range Imaging <[email protected]> > Subject: Re: [HDRI] Convert equisolidangular to equiangular projection > Message-ID: <[email protected]> > Content-Type: text/plain; charset="utf-8" > > > > If it is of any interest I did this overview some years back concerning > various projections > > > > [cid:[email protected]] > > > Claus B. Madsen > > Assoc. Prof., Ph.D. | Department of Architecture and Media Technology > > > > Phone: +45 9940 8788 | E-mail: [email protected]<mailto:[email protected]> > > Aalborg University | Rendsburggade 14 | 9000 Aalborg | Denmark > > > > Employee No.: 107255 | Vat No.: DK29102384 > > > > From: "J. Alstan Jakubiec" <[email protected]> > Reply-To: High Dynamic Range Imaging <[email protected]> > Date: Thursday, 26 January 2017 at 06.57 > To: "[email protected]" <[email protected]> > Subject: Re: [HDRI] Convert equisolidangular to equiangular projection > > > Hi Zhe, > > As far as I am aware, the Sigma 8mm f/3.5 is an equi-angular (-vta) lens, > and the Sigma 4.5mm f/2.8 is an equi-solid angle (-???) lens. I am having > trouble finding a source from Sigma right now, but Cauwerts, Bodart and > Deneyer's paper<http://www.tandfonline.com/doi/abs/10.1582/LEUKOS. > 2012.08.03.002> says so. > That said, if you do end up with an equi-solidangle image, I have a python > script that converts equi-solid angle to equi-angle for each source jpeg > while maintaining the EXIF data. I used this to convert equi-solidangle > images from my Canon 8-15mm fisheye lenses. > > Best, > Alstan > On 1/26/2017 8:48 AM, Gregory J. Ward wrote: > > Hi Zhe, > > > > You should be able to apply the fisheye_corr.cal file I gave you earlier > to correct the distortion and make it an angular fisheye image that pinterp > works with. (Why you need pinterp, I am not sure.) The command is as > suggested in the fisheye_corr.cal file itself: > > > > pcomb -f fisheye_corr.cal -o fisheye.hdr \ > > | getinfo -a "VIEW= -vta -vh 180 -vv 180" \ > > > corrected.hdr > > > > This will also crop the area outside of 180? to black, assuming that is > what you want. It assumes that you have already cropped the image to a > minimum square area. You should apply vignetting correction and absolute > calibration first. > > > > Cheers, > > -Greg > > > > From: Zhe Kong <[email protected]><mailto:[email protected]> > > Date: January 25, 2017 1:15:49 PM PST > > > > Dear list: > > I am trying to compare HDR images and simulated luminance maps. Since I > use SIGMA 8mm 1:3.5 for Canon, I need to convert equisolid-angular to > equiangular project. I see very useful information from the post below: > > > > https://www.radiance-online.org:447/pipermail/radiance- > general/2015-August/011184.html > > > > However, I still have some questions need to figure out. > > 1) pinterp does not include equisolid-angular projection, so a equation > needs to be applied to the function. Greg mentioned this simple expression, > sin(theta)/theta, but I am still confused. Could anyone offer me the > command? > > > > 2) The post discussed the steps of processing HDR images. If I get it > right, the steps following "adjust exposure" are vignetting correction, > adding view information, converting project from equisolidangular to > equiangular, then calibrating the image. I use a GOSSEN Starlite 2 to > record the luminance value on a grey card for calibration. My question is, > should I calibrate the image before or after converting fisheye projection? > > > > Any suggestions or explanation would be appreciated. > > Zhe > > > > _______________________________________________ > > HDRI mailing list > > [email protected]<mailto:[email protected]> > > http://www.radiance-online.org/mailman/listinfo/hdri > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://www.radiance-online.org/pipermail/hdri/ > attachments/20170126/1413ac46/attachment.html> > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: image001.png > Type: image/png > Size: 5434 bytes > Desc: image001.png > URL: <http://www.radiance-online.org/pipermail/hdri/ > attachments/20170126/1413ac46/attachment.png> > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: hemispherical.pdf > Type: application/pdf > Size: 758144 bytes > Desc: hemispherical.pdf > URL: <http://www.radiance-online.org/pipermail/hdri/ > attachments/20170126/1413ac46/attachment.pdf> > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > HDRI mailing list > [email protected] > http://www.radiance-online.org/mailman/listinfo/hdri > > > ------------------------------ > > End of HDRI Digest, Vol 87, Issue 1 > *********************************** > -- *Zhe Kong* *PhD Student* *University of Wisconsin - Milwaukee * *School of Architecture and Urban Planning * *2131 E. Hartford Ave, Milwaukee, WI 53211 * *Office 327*
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