IRC log for #brlcad on 20130618

00:18.38 DarkCalf waves to #brlcad
00:37.54 *** join/#brlcad kesha_ (~kesha@49.248.244.66)
00:58.32 *** join/#brlcad kesha_ (~kesha@49.248.244.66)
01:05.49 *** join/#brlcad kesha_ (~kesha@49.248.244.66)
01:55.18 *** join/#brlcad kesha_ (~kesha@49.248.244.66)
02:14.47 *** join/#brlcad kesha_ (~kesha@49.248.244.66)
03:40.04 *** join/#brlcad zero_level (~zero_leve@117.205.23.195)
03:45.40 *** join/#brlcad KimK (~Kim__@wsip-184-176-200-171.ks.ks.cox.net)
04:05.53 *** join/#brlcad zero_level (~zero_leve@117.212.30.199)
04:30.36 *** join/#brlcad zero_level (~zero_leve@117.220.8.156)
04:35.50 *** join/#brlcad zero_level (~zero_leve@117.220.8.156)
04:39.43 *** join/#brlcad harmanpreet (~chatzilla@202.164.53.117)
04:45.02 *** join/#brlcad KimK (~Kim__@wsip-184-176-200-171.ks.ks.cox.net)
04:53.59 *** join/#brlcad KimK (~Kim__@wsip-184-176-200-171.ks.ks.cox.net)
04:54.27 *** join/#brlcad DarkCalf (~DarkCalf@173.231.40.99)
04:57.13 *** join/#brlcad zero_level (~zero_leve@117.212.25.75)
05:09.08 *** join/#brlcad harmanpreet (~chatzilla@202.164.53.117)
05:09.51 *** join/#brlcad DarkCalf (~DarkCalf@173.231.40.99)
05:17.27 *** join/#brlcad zero_level (~zero_leve@117.205.28.97)
05:33.05 Notify 03BRL-CAD Wiki:Harman052 * 5433 /wiki/User_talk:Harman052:
05:37.10 *** join/#brlcad harmanpreet (~chatzilla@202.164.53.117)
05:43.47 *** join/#brlcad KimK (~Kim__@wsip-184-176-200-171.ks.ks.cox.net)
06:17.57 *** join/#brlcad KimK (~Kim__@wsip-184-176-200-171.ks.ks.cox.net)
06:47.59 *** join/#brlcad harmanpreet (~chatzilla@202.164.53.117)
07:15.59 *** join/#brlcad crdueck (~cdk@24.212.219.10)
07:34.57 *** join/#brlcad harmanpreet (~chatzilla@202.164.53.117)
07:52.11 *** join/#brlcad harmanpreet (~chatzilla@202.164.53.117)
07:58.41 *** join/#brlcad harmanpreet (~chatzilla@202.164.53.117)
08:01.15 *** join/#brlcad crdueck (~cdk@24.212.219.10)
08:41.08 Notify 03BRL-CAD:phoenixyjll * 55795 brlcad/trunk/src/libbrep/intersect.cpp: Use macros to represent default tolerance and change it to 0.001 (the same as the default tolerance of curve/curve, curve/surface, surface/surface defined by openNURBS).
08:42.43 *** join/#brlcad zero_level (~zero_leve@117.205.30.31)
08:49.14 Notify 03BRL-CAD:phoenixyjll * 55796 brlcad/trunk/src/libbrep/intersect.cpp: The input u_domain and v_domain should be considered.
08:50.23 Notify 03BRL-CAD Wiki:Phoenix * 5434 /wiki/User:Phoenix/GSoc2013/Reports: /* Week 1 */
09:04.21 *** join/#brlcad zero_level (~zero_leve@117.205.27.5)
09:05.50 *** join/#brlcad vladbogo (~chatzilla@188.25.101.47)
09:22.36 Notify 03BRL-CAD Wiki:Vladbogolin * 5435 /wiki/User:Vladbogolin/GSoC2013/Logs:
10:06.08 *** join/#brlcad zero_level (~zero_leve@59.91.152.164)
10:32.48 *** join/#brlcad zero_level (~zero_leve@117.220.15.37)
11:01.31 *** join/#brlcad zero_level (~zero_leve@117.205.16.166)
11:30.17 *** join/#brlcad caen23 (~caen23@92.81.220.39)
11:39.31 zero_level hi Erik
11:39.43 zero_level just read ur comment on my bwhisteq patch
12:07.35 Notify 03BRL-CAD Wiki:Level zero * 5436 /wiki/User:Level_zero/patches: /* patch adding structure definitions in ICV.h */
12:12.40 *** join/#brlcad zero_level (~zero_leve@117.205.29.105)
12:41.35 *** join/#brlcad zero_level (~zero_leve@117.205.23.229)
12:54.26 *** join/#brlcad vladbogo (~chatzilla@188.25.101.47)
13:04.28 *** join/#brlcad zero_level (~zero_leve@117.205.26.159)
13:06.03 *** join/#brlcad kesha (~kesha@49.249.9.55)
13:13.33 *** join/#brlcad kesha_ (~kesha@49.249.19.83)
13:27.15 *** join/#brlcad zero_level (~zero_leve@117.212.30.1)
14:33.56 *** join/#brlcad KimK (~Kim__@wsip-184-176-200-171.ks.ks.cox.net)
15:25.36 Notify 03BRL-CAD Wiki:Fjibarguen * 0 /wiki/User:Fjibarguen:
15:46.57 *** join/#brlcad zero_level (~zero_leve@117.205.31.223)
15:51.59 zero_level hi ``Erik:
15:52.57 brlcad zero_level: talked briefly about bwhisteq
15:53.17 brlcad he looked at your patch, looks like you do preserve the existing behavior
15:53.29 brlcad it just looks like the existing behavior may be wrong :)
15:53.47 brlcad that tool hasn't been used or modified in a very LONG time
15:53.56 brlcad can you verify that it works?
15:54.09 brlcad or demonstrate that it doesn't?
15:54.28 zero_level but brlcad : who do i compare it with ?
15:54.35 zero_level the matlab histeq ?
15:54.45 brlcad good question
15:54.59 zero_level both will be way different
15:55.16 brlcad you could make a test file that has known values perhaps, like a 256x256 image with a gradient going from 0 to 255
15:55.34 brlcad something so you'd know whether the result is "correct"
15:55.40 brlcad or compare to matlab
15:55.52 zero_level moreover, i still think both the implementation are same !
15:55.56 brlcad don't want to spend too much time on it since it is so old
15:56.04 zero_level my patch and previous implementation
15:56.12 brlcad if it works, great, something might need to be documented
15:56.43 brlcad zero_level: yeah, that's understood now -- you just uncovered what seems like might be a pre-existing bug
15:56.46 brlcad no worries
15:57.07 brlcad if it doesn't work, we can do a quick eval to decide whether it's worth fixing
15:57.18 brlcad need to know if it's right/wrong though
15:57.23 zero_level ok
15:57.28 brlcad can you figure it out? :)
15:57.32 brlcad quickly :)
15:58.03 brlcad (just don't want anyone to spend days on this)
15:59.30 zero_level i procedding it this way. --create a png file of uniform gradient using matlab--converting it using bw-png --using bw-histeq(existing) and bwhisteq(after patch)
15:59.44 zero_level the resultant must not have much difference
15:59.52 zero_level is this methodology fine ?
16:07.59 zero_level brlcad: any inputs about my methodology ?
16:08.33 brlcad hopefully you'd use png-bw... ;)
16:09.19 brlcad zero_level: so short answer - no
16:09.37 brlcad there's no question about your patch any longer, I believe
16:10.08 brlcad the question is wether bwhisteq (before or after patch) is actually correct or not
16:10.21 brlcad nothing to do with the patch
16:10.30 zero_level that i understood :-)
16:10.52 zero_level so, my methodology about working of bwhisteq ?
16:10.58 zero_level yes png-bw
16:11.17 brlcad oh, I see you're telling me what you DID
16:11.19 brlcad that's fine
16:11.29 brlcad we're past that
16:11.31 brlcad :)
16:13.05 zero_level no it is what i am doing to verify bwhisteq, after ur suggestion
16:13.45 brlcad but how does that verify whether bwhisteq is correct?
16:13.56 brlcad it just verifies your patch preserves behavior
16:14.01 brlcad now whether the behavior is right
16:16.09 brlcad s/now/net/
16:16.11 zero_level yes since the image is of equal bins. therefore bwhisteq must not change the image.
16:16.34 brlcad can't type toay apprently
16:18.14 brlcad what does bwhisteq actually do?
16:18.35 brlcad rather what is it "supposed" to do?
16:19.17 zero_level it equalizes the histogram
16:20.10 zero_level so i am giving it an image which has same number of pixels of intensities from 0 to 255
16:20.21 brlcad <PROTECTED>
16:21.19 brlcad so takes a single 1-byte channel image file with intensity values
16:21.52 brlcad presumably finds the max to min range, maps that to 0-255, writes out new single 1-byte channel image?
16:24.39 zero_level to equalize, yes!
16:25.14 brlcad okay, just making sure we're on the same page of understanding
16:25.57 brlcad so then gradient test is fine, but only mildly useful in that it should provide no change
16:27.44 brlcad I'd suggest also testing three more images: one with half black and half 128, another with half white and half 128, and last with half 128 and half 127
16:28.04 brlcad can then just visually inspect to make sure all three turn into half black half white
16:28.33 zero_level ok
16:57.46 *** join/#brlcad harmanpreet (~chatzilla@210.56.121.229)
17:09.41 zero_level brlcad : only for the first case(uniform) the answer is right
17:09.48 zero_level for the rest it is not right
17:10.18 zero_level it is converting to (127 - 128) combination
17:11.34 *** join/#brlcad jordisayol (~jordisayo@unaffiliated/jordisayol)
17:14.15 zero_level no it is converting to (63,191)
17:14.45 zero_level the lighter gets conveted to 191 and the darker gets coverted to 63
17:15.14 zero_level the lighter half and the darker half
17:24.48 Notify 03BRL-CAD Wiki:Harman052 * 5437 /wiki/User:Harman052: Formatting Improved.
17:26.04 *** join/#brlcad kesha_ (~kesha@49.249.200.67)
17:27.09 *** join/#brlcad jordisayol (~jordisayo@unaffiliated/jordisayol)
17:34.52 *** join/#brlcad zero_level (~zero_leve@117.205.17.121)
17:54.56 *** part/#brlcad zero_level (~zero_leve@117.205.17.121)
17:54.58 *** join/#brlcad zero_level (~zero_leve@117.205.17.121)
18:09.15 Notify 03BRL-CAD Wiki:Harman052 * 5438 /wiki/User:Harman052/GSoc2013/Logs: Details Updated
18:29.03 *** part/#brlcad jordisayol (~jordisayo@unaffiliated/jordisayol)
18:36.07 *** join/#brlcad zero_level (~zero_leve@117.205.24.89)
18:52.32 *** join/#brlcad kesha_ (~kesha@49.249.200.67)
18:57.31 *** join/#brlcad kesha_ (~kesha@49.249.200.67)
19:03.04 *** join/#brlcad zero_level (~zero_leve@117.205.16.250)
19:34.46 *** join/#brlcad zero_level (~zero_leve@117.205.16.149)
19:49.13 *** join/#brlcad Ch3ck (29cac1fa@gateway/web/freenode/ip.41.202.193.250)
19:49.47 Ch3ck just made a new patch for the new push routine with the additional ability to recognise
19:50.12 Ch3ck a push -x in case there is no -x option as in push -x or xpush(deprecated)
19:50.21 Ch3ck also concerning my pull routine
19:51.20 Ch3ck i wish to know if brlcad has an implementation of the inverse of a 4x4 matrix so i could get started on studying the libged libraries and other associated libraries related to my project.
19:51.48 *** join/#brlcad mpictor (~mark@2601:d:b280:9:d63d:7eff:fe2d:2505)
19:57.59 *** join/#brlcad Izak (29cac1fa@gateway/web/freenode/ip.41.202.193.250)
19:58.46 Izak <PROTECTED>
20:17.02 brlcad Ch3ck: saw the patch, comments coming soon
20:17.14 Ch3ck yeah
20:17.16 brlcad there is some inverse logic, but very limited
20:17.26 Ch3ck it was just the full source code
20:17.35 Ch3ck i am trying to upload a modified one
20:17.40 brlcad ah, did not see that
20:17.41 Ch3ck but network sucks.
20:17.46 brlcad patches should be just patches... :)
20:17.52 brlcad svn diff
20:17.53 Ch3ck yeah
20:18.05 Ch3ck i did that today
20:18.09 Ch3ck just recovered from malaria
20:18.22 Ch3ck so came back stronger today..
20:18.59 zero_level brlcad: I saw the result
20:19.08 zero_level those were not right
20:19.15 zero_level just got the hold of the source
20:19.41 zero_level working to modify that
20:19.48 brlcad Ch3ck: glad to hear you recovered!
20:19.55 brlcad no recovering would have kinda sucked... :)
20:20.12 brlcad zero_level: okay, so any notion of whether it'll be easy to fix?
20:21.30 zero_level i am considering to fully modify the code after calculation of bins
20:21.58 *** join/#brlcad Ch3ck_ (29cac1fa@gateway/web/freenode/ip.41.202.193.250)
20:22.03 zero_level also i thing this may be one of the brlcad's premitive function
20:22.21 zero_level may be it works for something else.
20:22.30 brlcad maybe what works?
20:22.59 zero_level may be this alorithim does something in the name of the histogram equalization!
20:23.11 brlcad you mean something else, like just poorly named?
20:23.14 zero_level so do u want me to modify this file or add a new one ?
20:23.16 zero_level yes!
20:23.41 brlcad well if that's not obvious from the file's contents, we don't need to spend time figuring it out
20:24.08 brlcad you could search the history, see if the comments tell you anything
20:24.21 zero_level history of bwhisteq ?
20:24.35 brlcad prior to r22000, that file would have been in the top-level util directory I believe
20:24.44 brlcad yes
20:24.59 brlcad or if there are any other utilities similarly named
20:25.05 brlcad that deal with histograms
20:25.28 brlcad does pixhist work alright?
20:25.58 zero_level we dont have a histogram equalization for pix
20:25.59 brlcad pixhist3d is another, pixhist3d-pl
20:26.17 zero_level that i suppose is performed by using pix-bw3
20:27.01 zero_level and then bwhisteq and then bw3-pix
20:27.42 zero_level using bwhisteq meant performing equalization on each channel and then combining
20:28.23 brlcad so what is ill-defined is what is meant by "equalized"
20:28.49 zero_level the interesting point as i saw was when there were two different halfs of different intensities as the resultant of the three cases u said
20:29.27 brlcad if you have a half 0/0/0 and half 255/255/255 image, those are either already "equal" (assuming equal area) .. or their intensities still need to be "balanced"
20:29.29 zero_level and all these were 63 for the darker half and 191 for the lighter half
20:29.32 Ch3ck_ brlcad: you were saying..
20:30.10 zero_level what i saw from the result were two buildings in the histogram at 63 and 191
20:30.17 brlcad zero_level: yeah that is _also_ an equalization of sorts ... just an unusual one (to me)
20:30.18 zero_level which makes it balanced
20:30.28 zero_level yes!
20:32.33 zero_level but when we read the code it is not the the normal mapping as u explained
20:32.47 zero_level do u want me test on lena image.. ?
20:35.31 brlcad zero_level: sure, would be good to see what it does
20:36.06 brlcad if it's useful, we can keep it as is
20:36.08 zero_level brlcad: was already on it!
20:36.21 brlcad if we keep it, we should document this behavior (better)
20:36.37 brlcad if it's not useful or only marginally so, we can get rid of it
20:37.13 zero_level brlcad: ok !
21:18.00 zero_level checked for barbara and lena works fine.
21:18.14 zero_level i am finding a way to post them on wiki so that u can see that
21:18.21 zero_level brlcad:
21:27.27 zero_level brlcad find the images here barabara : http://tinypic.com/r/2rqeubl/5 barabara equalized : http://tinypic.com/r/71gq6q/5 lena : http://tinypic.com/r/33krogg/5 lena equalized : http://tinypic.com/r/10r2sti/5
21:33.28 *** join/#brlcad KimK (~Kim__@wsip-184-176-200-171.ks.ks.cox.net)
21:39.21 brlcad zero_level: okay, so on the surface I'd say that's more than marginally useful
21:39.34 brlcad so keep on, it's fine
21:40.10 zero_level i still wonder about the working of the code. Either it is state of the art. or can be improved significantly
21:40.28 brlcad yep
21:40.45 brlcad in this case, it's certainly not state of the art, but it is still useful
21:40.51 zero_level also saw CxImage library there also they implement in the general way where we map the pixels
21:40.57 brlcad just not an active area of development and hasn't been for probably 20 years
21:43.08 brlcad zero_level: so if you try equalize in cximage, do you get the same result?
21:43.27 brlcad maybe also try "normalize"
21:44.08 zero_level didnt install the library but the code is entirely different
21:44.17 zero_level checked with matlab histeq function
21:44.20 zero_level there are differe
21:44.25 zero_level *different
21:44.38 brlcad they have a demo app: http://www.codeproject.com/Articles/1300/CxImage
21:44.49 brlcad that shows equalize and normalize
21:48.05 zero_level the matlab histeq are slightly different. on seeing one cannot find the difference. but pixel wise differences are observed using subtraction
21:48.55 brlcad pixdiff tool will show you the differences
21:49.22 brlcad still "slightly different" is informative
21:49.57 brlcad could imply a round-off error or off-by-one bug or edge case handled differently or just an entirely different (but similar) method altogether
21:51.52 brlcad did you do histeq(I, 256) in matlab?
21:52.22 brlcad default is 64
21:52.44 zero_level i did only histeq(I)
21:52.54 brlcad so that's probably the difference
21:52.58 zero_level ok
21:53.00 brlcad try 256
21:54.10 brlcad I like that you're comparing with matlab.... :)
21:54.39 zero_level i did with 256 this tym
21:55.06 brlcad BRL-CAD has MANY parallels with Matlab in terms of design, history, commands, low-level functionality
21:56.09 zero_level the sum of abs diff for pixels is 70434 for 263144 pixels
21:56.17 zero_level *262144
21:56.30 zero_level for the barbara image
21:56.39 zero_level i think this is negligible
21:56.45 brlcad hm, how diff?
21:56.50 brlcad what does pixdiff say?
22:03.48 zero_level pixdiff bytes: 191709 matching, 70434 off by 1, 0 off by many
22:04.06 brlcad nice, so that is basically matching with some round-off error
22:04.12 zero_level this is the result of pixdiff on barbara equlaized with matlab and bwhisteq
22:04.38 brlcad it'd be iteresting to figure out who has the rounding error
22:04.57 brlcad could be either, that's a very tiny difference
22:05.46 brlcad given our tools usage, my bets would be on it having a rounding issue but that's still surprisingly good
22:05.54 brlcad and reinforces the value of the tool
22:15.30 zero_level brlcad: about that mail
22:15.47 zero_level because it has few things regarding the development plan
22:16.20 zero_level also those whole sum is because of 1 pixel intensity difference
22:17.45 brlcad <PROTECTED>
22:18.03 brlcad like 128/128/128 vs 128/127/128
22:18.10 *** join/#brlcad zero_level (~zero_leve@117.205.16.149)
22:18.16 brlcad <PROTECTED>
22:18.19 brlcad like 128/128/128 vs 128/127/128
22:18.34 brlcad not even 127/127/127 vs 128/128/127
22:22.34 *** join/#brlcad zero_level (~zero_leve@117.205.16.149)
22:37.01 *** join/#brlcad zero_level (75cd1727@gateway/web/freenode/ip.117.205.23.39)
22:37.57 *** join/#brlcad zero_level_ (~zero_leve@117.205.23.39)

Generated by irclog2html.pl Modified by Tim Riker to work with infobot.