[Radiance-general] help pfilt and low values dgp

Jasper Overduin overduin.jasper at gmail.com
Sun Aug 16 13:14:28 PDT 2015 

Thanks a lot for the help so far. I've updated the evalglare to 1.11.
Getting the same results as Jan showed.

I've desinstalled and reinstalled everything, and now the pcompos and other
functions are not recognized. With a google search I couldnt find the
problem.

any ideas?

installed
radiance 2.01
daysim 4.0
ecotect 2011
evalglare 1.11

As far as the picture. This is the only photo with an almost direct sun.
Other photos (160) are within a more sober spectrum. The idea is to to an
analysis of cd/m2 ratios, with the evalglare as indicator, not as main
target. Do you think it is possible to use the data?

Greetings,
Jasper



*Jasper Overduin*
MSc. Building Technology graduate student at Delft University of Technology


*S* Groenhoevelaan 3
*P* 2343 BP Oegstgeest
*T* +31 6 15 64 48 56 (NL)
*T* +56 9 51 11 76 48 (CL)
*E *overduin.jasper at gmail.com
*Skype *jasper.overduin

On 13 August 2015 at 11:23, Jan Wienold <jan.wienold at epfl.ch> wrote:

> Hi Jasper,
>
> you definitely should use a newer version of evalglare.
> If you go to the website:
> http://www.ise.fraunhofer.de/radiance
> you can at least download the 1.11 version-which doesn't have this bug.
>
> The will be a new version of evalglare coming out in the next days/weeks
> (version 1.17) - this will be announced separately here in that group.
>
> Regarding your image: Your calibration must span the luminance-range you
> want to measure.
> If you calibrate between 1cd/m2-1000 cd/m2 it does not tell you anything
> how accurate you are when measuring 100000cd/m2!
> So if you want to measure the luminance of the sun, then you have to make
> sure your camera is calibrated for such high luminances as well.
> I guess when you want to measure several million cd/m2 you might need a
> grey filter. At ISE we had several filters down to 0.0001 transmittance, so
> it was easy to measure also towards the sun and the increase of noise for
> the lower luminaces doesn't hurt so much.
> Your coating on the window play a minor role in that case... honestly for
> the sun you can be lucky to measure with one or 2 orders of  magnitude, so
> if your glazing is 0.75 or 0.4 in light transmittance is negligible
> compared to the difference between 5000 and 200000000 cd/m2 !
>
> The picture you have in dropbox is also difficult to check with an
> illuminance meter when you integrate the values to an illuminance value,
> because the sun is so much on the side and has a very flat angle of
> incidence to your measuring plane. For example when your angle of incidence
> for the light source (here sun) is 80° and your "uncertainty" for putting
> the sensor in the right plane wold be 2.5 degree (it is very difficult to
> put it more accurate), then you have automatically an uncertainty in your
> sensor reading of 25% (of the illuminance)! (because illuminance is
> cos-weighted and a difference in angle for large angles is big for the
> cosinus).
>
> Good luck!
>
> best,
> Jan
>
>
>
>
>
>
> Am 8/12/15 um 3:21 PM schrieb Jasper Overduin:
>
> Im using evalglare 1.10 release 30.09.2012 with windows 7
> The photos are calibrated with a (il)lumination pistol with 4 different
> measurements (with maximum deviation of 0.4 cd/m2)
> There is a certain coating on the window, not sure what kind. but as you
> said the difference is huge.
>
> Within the program of HDRscope there is a similar function and gives and
> errer as well if i use an external Ev value.
>
> Greetings,
> Jasper
>
>
>
>
>
>
> *Jasper Overduin*
> MSc. Building Technology graduate student at Delft University of Technology
>
>
> *S* Groenhoevelaan 3
> *P* 2343 BP Oegstgeest
> *T* +31 6 15 64 48 56 (NL)
> *T* +56 9 51 11 76 48 (CL)
> *E * <overduin.jasper at gmail.com>overduin.jasper at gmail.com
> *Skype *jasper.overduin
>
> On 12 August 2015 at 06:39, Jan Wienold <jan.wienold at epfl.ch> wrote:
>
>> Hi Jasper,
>> hi Alstan,
>>
>> I guess there are several issues in that case. First of all, as Alstan
>> wrote, you should crop the image and provide the correct lens specification
>> to evalglare. Be aware that editing the header could be dangerous, because
>> sometimes editors add strange characters or you don't see tabs in the
>> header with marks the view string there as "invalid" . In case the header
>> is interpreted "wrong" in evalglare, the results could be really random and
>> could differ for more than 100% from the right ones (e.g. the calculation
>> of the vertical illuminance, see presentation on the Radiance workshop in
>> 2012). The header treatment is much more robust since the evalglare version
>> 1.08, but still the user should take care of providing a correct header.
>> evalglare is relying on a correct radiance header. To be on the safe side,
>> you should always use the command option to provide the correct view option
>> to evalglare.
>> Also you should make sure, that you use a view type which really
>> corresponds to your lens. If your real lens is a hemispherical fish eye and
>> you provide  -vta as view string, the angles and solid angles are
>> calculated wrong in evalglare and you get wrong results. So make sure that
>> you use -vta only if your lens is a angular fish eye.
>> And please don't use the -1 option in evalglare!!! This is a special
>> (undocumented) option to get fast results on images calculated without
>> ambient calculations. If you use it for normal images, the glare sources
>> might not detected correctly and you could get big differences. It is
>> working mostly properly in images with large black areas (-ab 0).
>> Since the -1 option is not robust for normal images, this option is
>> undocumented. There exist also other undocumented options since 2009 for
>> hdr treatment(e.g. pixel overflow correction, image fillup when ccd-array
>> is smaller than the projected image...), but these options are by purpose
>> undocumented because they should be used only in special cases and can
>> cause wrong results when not used properly.
>>
>> If I look at your image, I guess your calibration is not correct. The sun
>> has a luminance of 2e10 cd/m2. In case of low transmittance glazing you
>> still have a luminance of  Xe9 cd/m2, lets say at least 1e9cd/m2, which is
>> factor 200000 higher than you measured!!! And be aware you you might have
>> to deal with blooming  effects when you have a pixel overflow (especially
>> when looking into the sun). Not sure about your camera setting, but if you
>> still have an overflow for the shortest exposure, you should think of
>> adding a neutral grey filter to reduce the overall transmittance to the ccd.
>>
>> Finally I can't reproduce the 0 output of evalglare. I used your image
>> and used as well the 2500lux as input (even if the image is not cropped
>> correctly and the view string is wrong). See here:
>> *evalglare -i 2500 pmar_sin_03.hdr*
>> *Notice: Low brightness scene. Vertical illuminance less than 380 lux!
>> dgp might underestimate glare sources*
>> *dgp,dgi,ugr,vcp,cgi,Lveil: 0.311778 18.132195 21.670120 44.798004
>> 27.925421 58.052605  *
>>
>> But I always get an non-0 result, I never experienced this before. I
>> tried the linux ,the mac and also the windows version with your image - it
>> didn't happen. So which version are you using? Which operating system?
>> (type evalglare -v to find out)
>>
>> @Alstan: Can you provide me another example where this happens as well?
>> Which version are you using? Which operating system?
>>
>> A zero value should never appear, except your image is completely black.
>>
>> Best,
>> Jan
>>
>>
>>
>> Am 8/11/15 um 5:33 PM schrieb J. Alstan Jakubiec:
>>
>> Hi Jasper,
>>
>> This is one of the tricky aspects of doing glare analysis with your own
>> HDR images. A couple of pointers are below,
>>
>>    - You will need to crop your image to a square aspect about the image
>>    center using the pcompos
>>    <http://radsite.lbl.gov/radiance/man_html/pcompos.1.html> tool. There
>>    was a helpful discussion on maintaining image exposure values while doing
>>    this here
>>    <http://www.radiance-online.org/pipermail/radiance-general/2011-March/007701.html>
>>    .
>>    - The -vv and -vh parameters are just best guesses according the HDR
>>    generation software. Once you have cropped the image, you will want to open
>>    the resulting HDR in a text editor and manually change the header 'VIEW'
>>    field to include -vta -vv 180 -vh 180. You may also specify them via
>>    the command line at this point, as you have done. I like to keep it
>>    associated with the image.
>>    - After that, unless I am forgetting something (others can chime in),
>>    you are ready to run evalglare. I would run it with the -d flag,
>>    which will report a lot of details. Most usefully, it reports illuminance
>>    as derived from the image, which you can compare to your measured Ev value
>>    to check the validity of the HDR. If your HDR is well-calibrated, not
>>    inputting the measured illuminance value should be perfectly accurate.
>>    - I suspect that inputting measured illuminance is somewhat broken in
>>    the current version of evalglare as I have the same problem that you do.
>>    One option is to use the -1 option to evalglare, which will return
>>    only a single DGP value. It seems to avoid this error.
>>    > evalglare -1 -i 2500 image.hdr
>>
>> By the way, to avoid some of this cropping and exposure value pain, I use
>> an image-processing tool (like PIL for Python) these days that can maintain
>> EXIF data while cropping the source jpeg files. Though perhaps the cure is
>> worse than the disease in this case..
>>
>> Best,
>> Alstan
>>
>> On 8/11/2015 11:08 PM, Jasper Overduin wrote:
>>
>> Dear all,
>>
>> I have changed my lens to one with 180 circular view to do a contrast
>> analysis (hdrscope) and meanwhile the glare analysis in evalglare. If i use
>> the commands in evalglare getinfo i get the (HDR composed with photosphere
>> on a mac, calibrated with luminance pistol) i get a value for the lens -vv
>> and -vh which is not over 100, with a lens of 180. I can imagine that the
>> photo ratio and the lens are not the same and that causes this problem. But
>> when I enter the external measured Ev, the value the dgp goes somehow to
>> zero. The fact that the gdp is zero with a maximum luminance of 5600 cd/m2
>> and Ev of 2500 lux makes me a bit suspicious. How accurate is the result of
>> the dgp without external vertical lux? is it possible to use this value?
>>
>> hdr files and printscreens of evalglare
>> <https://www.dropbox.com/sh/ei1y4d2v6hapdsr/AACgVMPd1o0EdK-0q8CFvUGga?dl=0>
>> https://www.dropbox.com/sh/ei1y4d2v6hapdsr/AACgVMPd1o0EdK-0q8CFvUGga?dl=0
>>
>>
>> Greetings Jasper
>>
>>
>>
>> *Jasper Overduin*
>> MSc. Building Technology graduate student at Delft University of
>> Technology
>>
>>
>> *S* Groenhoevelaan 3
>> *P* 2343 BP Oegstgeest
>> *T* +31 6 15 64 48 56 (NL)
>> *T* +56 9 51 11 76 48 (CL)
>> *E * <overduin.jasper at gmail.com>overduin.jasper at gmail.com
>> *Skype *jasper.overduin
>>
>> On 1 May 2015 at 12:15, Jan Wienold < <jan.wienold at epfl.ch>
>> jan.wienold at epfl.ch> wrote:
>>
>>> Hi Jasper,
>>>
>>> I briefly looked at your image - for sure you get a low DGP value if
>>> your illuminance at camera (or eye) level is only about 300lux... It is not
>>> the matter of the fish eye lens it is a matter of your lighting condition.
>>> When I remember correctly, for the experiments I did for my PhD, the
>>> people adjusted the blinds in a way, that they had 2500-3000 lux at the eye
>>> level and they were less than 20% of them dissatisfied. So a value of 300
>>> means one order of magnitude less light at the eye level and a much lower
>>> adaptation level.
>>> So I definitely understand the low DGP value in that case. The images
>>> themselves look reasonable, so I don't think there is a problem in
>>> calibration/processing so far (at least not for these low luminance
>>> levels-it might be more tricky to calibrate for the high luminance values
>>> when you get stray-light from the multiple lenses).
>>>
>>> If all your images are like that it means you have a very low daylight
>>> contribution at the place you measure. I'm not sure if DGP is then the
>>> right way to measure glare in that case - as I wrote it is made more for
>>> the daylight oriented workplace with higher levels and also to take into
>>> account very high luminances (e.g. sun or specular reflections of the sun).
>>> DGP might be modified in future, but these experiments are just starting.
>>>
>>> Jan
>>>
>>>
>>>
>>>
>>>
>>>
>>> Am 4/30/15 um 10:41 PM schrieb Jasper Overduin:
>>>
>>> Thank you for the fast reply. We are still having some problems with the
>>>> outcome of Evalglare. With an external luxometre we have done some tests
>>>> now. The DGP is still very low or zero. It seems that in almost all the
>>>> case the DGP is low. In literature we read that values above 20% are
>>>> normal. What do you think? is the data much better if we use a full 180
>>>> degree lens?
>>>>
>>>> .hdr file <https://www.dropbox.com/s/l10x7tri49btr8r/ff.hdr?dl=0>
>>> https://www.dropbox.com/s/l10x7tri49btr8r/ff.hdr?dl=0
>>> print screen cmd
>>> <https://www.dropbox.com/s/yv1lamhiirjhvxq/imp%20pan.jpg?dl=0>
>>> https://www.dropbox.com/s/yv1lamhiirjhvxq/imp%20pan.jpg?dl=0
>>> test.pic  <https://www.dropbox.com/s/nspdu01477mchsz/test.pic?dl=0>
>>> https://www.dropbox.com/s/nspdu01477mchsz/test.pic?dl=0
>>>
>>>
>>>> Greetings Jasper
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *Jasper Overduin*
>>>> MSc Building Technology graduate student at Delft University of
>>>> Technology
>>>>
>>>> *S* Groenhoevelaan 3
>>>> *P* 2343 BP Oegstgeest
>>>> *T* +31 6 15 64 48 56 (NL)
>>>> *T* +56 9 51 11 76 48 (CL)
>>>> *E * <overduin.jasper at gmail.com>overduin.jasper at gmail.com
>>>> *Skype *jasper.overduin
>>>>
>>>> On 30 April 2015 at 13:55, Jan Wienold < <jan.wienold at epfl.ch>
>>>> jan.wienold at epfl.ch> wrote:
>>>>
>>>>> Hi Jasper,
>>>>>
>>>>> why are you using -vth -vh 140 -vv 80 when in your header of the HDR
>>>>> image the view is specified as  -vtv -vh 98.797409 -vv 75.402067 ?
>>>>> Manipulating the lense type is really dangerous - in that case you
>>>>> change from a perspective view to a hemispherical fish eye view, without
>>>>> changing the image!!
>>>>>
>>>>> If I apply evalglare for your image I get 0.17 as DGP (which is still
>>>>> very low, but you have only 2000cd/m2 as maximum value, so this can be
>>>>> expected). Be aware, that DGP accounts only for glare from a high amount of
>>>>> daylight and/or spots of extreme luminances (>50000cd/m2), but not for
>>>>> contrasted glare between task (e.g. Monitor) and immediate surroundings for
>>>>> lower adaptation levels. This is subject of current research (also here at
>>>>> EPFL) and there might be an extension of the DGP in future, depending on
>>>>> the outcome of new experiments.
>>>>>
>>>>> Back to the lens-type:
>>>>> It is extremely important, that the right view type is given to
>>>>> evalglare, otherwise ALL calculated values (it doesn't matter if this is
>>>>> evalglare or findglare) are wrong. These errors could be huge, more than
>>>>> 100% for calculating the illuminance out of a 180 degree image.
>>>>>
>>>>> If you manipulate an image by pcomb, in general the view is marked as
>>>>> "invalid" in the header, because with that tool you could manipulate the
>>>>> image in a way, that the original view is not valid any more. This is why
>>>>> from evalglare version 1.0 on a check on the header was included, because
>>>>> many people were creating wrong headers without knowing it and then
>>>>> evalglare was calculating wrong values, when the header was invalid.
>>>>>
>>>>> In addition for calculating the DGP it is important to have the
>>>>> illuminance at camera level. evalglare calculates this value out of the
>>>>> image. But if the image does not cover 180 degree, then the calculated
>>>>> value for the illuminance is too low. For that reason, the -i option was
>>>>> included, so you can provide the illuminance to evalglare (when you measure
>>>>> it with an illuminance sensor).
>>>>>
>>>>> So in your case, you should measure the illuminance just besides the
>>>>> lens.
>>>>> Then (in case this is the right lens description) you should use
>>>>> evalglare -i LUXVALUE -vtv -vh 98.797409 -vv 75.402067 IMAGE_NAME
>>>>> or better, if your task is always at the same place:
>>>>> evalglare -i LUXVALUE -vtv -vh 98.797409 -vv 75.402067  -T 395 230 .6
>>>>> -c CHECK_FILE_PICTURE IMAGE_NAME
>>>>>
>>>>> good luck!
>>>>>
>>>>> Jan
>>>>>
>>>>>
>>>>>
>>>>> Am 4/30/15 um 6:04 PM schrieb Jasper Overduin:
>>>>>
>>>>> Somehow cant use the command pfilt or change the pcomb, does this has
>>>>> to do with the program Radiance? I have installed the version of windows
>>>>> from the site, with evalglare v1.11windows . The problem is that I have
>>>>> composed a .hdr (out of 7 jpg on a mac) and after using the command
>>>>> c:/HDRI>evalglare -vth -vh 140 -vv 80 image.hdr all the dgp results are
>>>>> really low, less than 5%. The problem can be in the .hdr (calibrated as
>>>>> well) or is in the way evalglare is not working as it shoot on my computer.
>>>>>
>>>>>
>>>>>
>>>>> *.hdr file* (post-it is calibration point 167,98)
>>>>> <https://www.dropbox.com/s/4z69y358yt8ii4z/1_sv_am.hdr?dl=0>
>>>>> https://www.dropbox.com/s/4z69y358yt8ii4z/1_sv_am.hdr?dl=0
>>>>> *images* original
>>>>> <https://www.dropbox.com/sh/adyyxjkv6eykyek/AAC96QUTpLh_Ef2U8Mppki8ta?dl=0>
>>>>> https://www.dropbox.com/sh/adyyxjkv6eykyek/AAC96QUTpLh_Ef2U8Mppki8ta?dl=0
>>>>> *command printscreen*
>>>>> <https://www.dropbox.com/s/0pbn105p0z0iinu/Imp%20pan.jpg?dl=0>
>>>>> https://www.dropbox.com/s/0pbn105p0z0iinu/Imp%20pan.jpg?dl=0
>>>>>
>>>>>
>>>>> Need the help!
>>>>>
>>>>> Greetings Jacobus
>>>>>
>>>>>
>>>>> *Jasper Overduin*
>>>>> MSc Building Technology graduate student at Delft University of
>>>>> Technology
>>>>>
>>>>> *S* Groenhoevelaan 3
>>>>> *P* 2343 BP Oegstgeest
>>>>> *T* +31 6 15 64 48 56 (NL)
>>>>> *T* +56 9 51 11 76 48 (CL)
>>>>> *E * <overduin.jasper at gmail.com>overduin.jasper at gmail.com
>>>>> *Skype *jasper.overduin
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Radiance-general mailing listRadiance-general at radiance-online.orghttp://www.radiance-online.org/mailman/listinfo/radiance-general
>>>>>
>>>>>
>>>>> --
>>>>> Dr.-Ing.  Jan Wienold
>>>>> Ecole Polytechnique Fédérale de Lausanne (EPFL)
>>>>> EPFL ENAC IA LIPID
>>>>> http://people.epfl.ch/jan.wienold
>>>>> LE 1 111 (Office)
>>>>> Phone    +41 21 69 30849
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Radiance-general mailing list
>>>>> <Radiance-general at radiance-online.org>
>>>>> Radiance-general at radiance-online.org
>>>>> <http://www.radiance-online.org/mailman/listinfo/radiance-general>
>>>>> http://www.radiance-online.org/mailman/listinfo/radiance-general
>>>>>
>>>>>
>>>>
>>>
>>>
>>> _______________________________________________
>>> Radiance-general mailing listRadiance-general at radiance-online.orghttp://www.radiance-online.org/mailman/listinfo/radiance-general
>>>
>>>
>>> --
>>> Dr.-Ing.  Jan Wienold
>>> Ecole Polytechnique Fédérale de Lausanne (EPFL)
>>> EPFL ENAC IA LIPID
>>> http://people.epfl.ch/jan.wienold
>>> LE 1 111 (Office)
>>> Phone    +41 21 69 30849
>>>
>>>
>>> _______________________________________________
>>> Radiance-general mailing list
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>>> http://www.radiance-online.org/mailman/listinfo/radiance-general
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>>>
>>
>>
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>>
>>
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>>
>> --
>> Dr.-Ing.  Jan Wienold
>> Ecole Polytechnique Fédérale de Lausanne (EPFL)
>> EPFL ENAC IA LIPID
>> http://people.epfl.ch/jan.wienold
>> LE 1 111 (Office)
>> Phone    +41 21 69 30849
>>
>>
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>
>
> _______________________________________________
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>
> --
> Dr.-Ing.  Jan Wienold
> Ecole Polytechnique Fédérale de Lausanne (EPFL)
> EPFL ENAC IA LIPID
> http://people.epfl.ch/jan.wienold
> LE 1 111 (Office)
> Phone    +41 21 69 30849
>
>
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