Hello Avinash,
There are two possible issues that I can think of: one regarding image
size (more likely culprit), and the second regarding metadata (less
likely). I am pretty sure the image size issue will solve your problem,
but you may also get improved results using images processed in a
slightly different way. Here are possible solutions:
SOLVING THE IMAGE SIZE ISSUE
Depending on the exact pixel count of your hdr, you need to make slight
adjustments to one of your image angle values. Using a camera and lens
similar to yours (Nikon D90 & AF-S Nikkor 35mm 1:1.8G), I collected a
series of raw and .jpg processed images. In my 3 experiments, I got the
following image sizes (shown with Matlab code):
nef = [4310 2868];
jp1= [4288 2848];
jp2= [1936 1286];
According to your notes, you set vv and vh as follows:
vv = 25.74
vh = 37.4
Now, I will recompute vv according to the pixel values and vh noted
above, which will show slightly different vv values:
vv_t1 = 2*atand(nef(2)/nef(1)*tand(vh/2))
vv_t2 = 2*atand(jp1(2)/jp1(1)*tand(vh/2))
vv_t3 = 2*atand(jp2(2)/jp2(1)*tand(vh/2))
Notice that the answers are slightly different than vv above:
vv_t1 = 25.3864
vv_t2 = 25.3403
vv_t3 = 25.3431
A detailed explanation is available in this posting from May 16, 1994:
http://radsite.lbl.gov/radiance/digests_html/v2n7.html#VIEW_ANGLES
SOLVING POSSIBLE METADATA ISSUE
I am not sure if this will help, but I suspect another culprit may be
either missing metadata in your Photoshop .jpg images, or (maybe but not
likely) the .hdr algorithm in Photoshop. I've tested the following 3
possible solutions using the same D90 and hdrgen wrapper variants--all
of which seem to preserve the metadata in the images, and produce
photometrically accurate results (list members, please correct me if I
am wrong about the above metadata assumptions)...
Method 1)
To process .nef images, see Greg's suggestion posted on February 20,
2012:
http://www.radiance-online.org/pipermail/hdri/2012-February/000363.html.
This seems to be the best raw to hdr method, as it seems to produce the
most photometrically accurate images.
My line of code looks like this: raw2hdr -o test01.hdr *.NEF (although I
should have included a calibration image).
Or, to use .jpg images, which are less accurate photometrically (but
still works), try either of the following procedures:
Method 2)
With .nef images still in the Nikon D90, use on-board post processing of
.nefs to .jpgs. That should give you the right metadata embedded in the
.jpgs, which may have been lost in the Photoshop .nef to .jpg conversion
process. I've tried this method, and it works. On the D90: Press
play-->select image-->press "ok"-->NEF (RAW) Processing-->(Chose your
favorite settings)-->EXE. Repeat that process for each image. Then
create the .hdr using hdrgen, Photosphere, or the online tool. I used
Photosphere in this case.
Method 3)
You can do batch processing (.nef->.jpg), using Nikon's ViewNX 2 on your
computer, as follows: Select your images, then: File-->Convert
Files-->Convert. I've also verified that images from this method work
with Photosphere. Or create .hdr with Photosphere, hdrgen, or the online
tool.
Note that with methods 2 or 3, you will have .jpg images that will be
processed using hdrgen or photosphere (or maybe Photoshop). Keep in mind
that Method 1 is the most difficult to set up, but will produce the best
(i.e., most photometrically accurate) results.
I hope these suggestions help (and don't lead you astray).
-Chris
On 4/23/13 10:31 PM, Avinash Gautam wrote:
I am trying to generate a hdri image from my camera Nikon D90 using
various lenses. My Nikon camera generates a .NEF file in RAW version
however I was able to generate a .HDR file using .JPG of the same
images in Photoshop. After I generated the .HDR file I tried running
evalglare on it which gives me an error. I understand I need to have a
fish eye lens to get the full view in order to get the correct results
but the purpose of my experiment is to test the error in dgp using
different lenses that are not fish eye lens. I am using the --vth
command and have entered the --vv and --vh as calculated for the 35mm
lens on a DX format camera (25.74degrees and 37.4degrees). This gives
me an error */pict_update_view: unknown view type /*and */error:
invalid view specified/*. Can anyone please let me know where I am
going wrong.
Thanks,
Avinash
//
_______________________________________________
HDRI mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/hdri
_______________________________________________
HDRI mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/hdri
