Michal Čihař - Posts tagged by photography

Sächsische Schweiz

I've enjoyed past extended weekend in Sächsische Schweiz. I really like this area and we've again seen there wonderful nature and climbed thousands of steps :-).

The weather was not that nice for taking photos, but still I can show few of them:

Niedermühle Kleiner Winterberg Aussicht Kleiner Winterberg Aussicht Kuhstahl Aussicht Bastei Bastei

Ruzyně airport

During weekend, I had great opportunity not only to visit Prague Airport, but also to taste airspotting. As photography is my hobby, this was interesting experience, though I don't think it would be my favorite thing to capture.

Anyway we could see some interesting places - L1011 TriStar KC1 from Royal Air Force, two Boeings 747-400F and Boeing 777-300. The Boeings being the biggest airplanes you can regularly see in Prague.

So lets stop talking and here are few pictures:

Prague carnivals

During these days, there are various carnivals in Prague. On Saturday I've visited Malostranský masopust, which is probably not the biggest one, but definitely the one in most attractive location, starting at Prague castle and going down to Kampa.

This was actually my first visit of this carnival and I quite enjoyed it. Bellow you can find some photos taken during the event to catch the atmosphere:

ColorHug with non English locales

Since infamous erasing of factory calibration in my ColorHug device and restoring calibration matrix, I noticed it did screen calibration wrong. However I did not find time to properly investigate the issue. Yesterdays mail from Richard was actually trigger for me so I've opened up this topic.

In the end it turned out to be caused by Little CMS wrongly parsing CCMX in case you are using locales which use something else than . as decimal point.

After lot of googling, I've realized there is probably no good way of parsing floats independent on current locales, so I used one of hacks I found and I think it's less intrusive - get current decimal point by printing float string using printf and then convert the string to it. I know it looks ugly, but including own implementation of strtod is also not nice and playing with locales is definitely something not thread safe to do within widely used library.

Anyway I've asked upstream to merge my patches, so let's see what they think of it.

ColorHug in openSUSE 12.1

Finally I've also find time to test ColorHug on openSUSE 12.1. For my experiences on Debian check previous blog post.

Unfortunately on openSUSE calibration is also not that easy. First of all, you have to install patched argyll CMS from multimedia:color_management repository. You can also install gnome-color-management (and colord), but for some reasons they did not offer me any screen for calibration, so I gave up on this and tried manual calibration using Argyll.

After looking into documentation, it seems to be pretty straightforward:

$ dispcal -y l -o /tmp/L220x
Place instrument on test window.
Hit Esc or Q to give up, any other key to continue:

Display adjustment menu:
Press 1 .. 7
1) Black level (CRT: Offset/Brightness)
2) White point (Color temperature, R,G,B, Gain/Contrast)
3) White level (CRT: Gain/Contrast, LCD: Brightness/Backlight)
4) Black point (R,G,B, Offset/Brightness)
5) Check all
6) Measure and set ambient for viewing condition adjustment
7) Continue on to calibration
8) Exit
Doing check measurements

  Current Brightness = 190.74
  Target 50% Level  = 36.14, Current = 47.98, error =  6.2%
  Target Near Black =  1.91, Current =  4.11, error =  1.2%
  Current white = x 0.3424, y 0.3179, VDT 5910K DE 2K 18.3
  Target black = x 0.3424, y 0.3179, Current = x 0.3123, y 0.2711, error = 18.06 DE

Press 1 .. 7
1) Black level (CRT: Offset/Brightness)
2) White point (Color temperature, R,G,B, Gain/Contrast)
3) White level (CRT: Gain/Contrast, LCD: Brightness/Backlight)
4) Black point (R,G,B, Offset/Brightness)
5) Check all
6) Measure and set ambient for viewing condition adjustment
7) Continue on to calibration
8) Exit
Commencing device calibration
The instrument can be removed from the screen.
$ dispwin -I /tmp/L220x.icc 
$ dispwin -L

It turned out, that the change after calibration are quite minor here. This is sort of thing I've expected from past experiences with editing photos here, but anyway, now I trust results here even more :-).

ColorHug has arrived

Yesterday, I've unpacked new toy - ColorHug. It came in small packet with CD (which is unfortunately not that useful as it should be), mini USB cable and a letter from Richard Hughes.

First attempt to use was of course just connect and make it work :-).

The basic access works out of the box:

$ /usr/lib/colorhug-client/colorhug get-firmware-version
1.0.3
$ /usr/lib/colorhug-client/colorhug get-hardware-version
Hardware Version 1
$ /usr/lib/colorhug-client/colorhug get-serial-number
000019

Unfortunately calibration with colord does not yet work out of the box on Debian due to bug 655888. Hopefully it will be fixed soon and it will work nicer. For now you have to rebuild Argyll with Colorhug support (with extra pain caused by Debian package using different build system than upstream). I won't provided binary packages as I pretty much gave up after effort to build clean packages from same sources on i386 and amd64, which always failed on patched autoconf based build system.

Side note: I somehow hoped that I won't hit new (in meaning that I don't know them) open source projects which do not use some version control. Unfortunately Argyll CMS is one of such projects...

After this update (and restarting GNOME), when connecting ColorHug, the Gnome Color Manager pops up and man can calibrate the screen. The biggest problem is to make ColorHug hold on desired place on screen, if it is not close enough to screen, you will get really bad results.

The first result is of course far from being perfect, but colors are definitely better than without calibration or with ICC profile shipped with notebook.

ColorHug for Debian and in Czech

Today, I've spent some time on ColorHug software (which I've preordered some time ago).

The first missing bit there were Debian packages. There are already some packages available for Ubuntu, but I've chosen clean start and did all the packaging on my own. The packages are now waiting in NEW queue (which is amazingly empty in last months) and will hopefully get accepted soon. In case you are too impatient, you can look to git repository on Alioth (you will need libgusb as well). Packaging effort lead to writing (quite minimalistic) man page for colorhug-ccmx, which I've also sent upstream.

The other thing, where I can help right now (not owning the device itself) is translation. As you can see on Transifex, my task is done here and Czech translation is complete :-).

Photo gallery, finally

In last weeks, I've finally managed to create my personal gallery, where I could present selection of my photographs. This task was outstanding on my todo list for pretty long time, the major obstacle being selecting photos which to present there.

During my sickness few weeks ago, I finally went through most of my photos and chosen the ones which I think are worth presenting. Still I did not manage to go through photos from half year spent in Japan, so these will be added sometimes later. Also most of the pictures miss descriptions, though I'm (slowly) fixing this.

From technical side, the gallery is being generated using lazygal with custom theme.

You can check the gallery on photos.cihar.com, I hope you will like it :-).

Photo of a week 18

Finally some outdoor morning photography from spring. Taken at fields near Hovořany.

Fields

Taken again using PENTAX K7 + PENTAX-DA 70mm F2.4 Limited.

Photo of a week 17

Finally some picture published on time. Going to slightly larger animals this week. Picture taken at parkour race in Prague.

Race

Taken again using PENTAX K7 + PENTAX-DA 70mm F2.4 Limited.

Photo of a week 16

Slightly delayed, but here comes photo for last week. I simply failed to download it from camera and process it. Continuing in animal macro, this time it is frog somewhere in Beskydy mountains.

Frog

Taken again using same combo PENTAX K7 + PENTAX-DA 35mm F2.8 Macro Limited.

Photo of a week 15

As you can see in week number, I failed to take photo every week. Nevertheless I will try to continue, maybe I won't skip that much. To compensate it a little, I've decided to publish two photos taken in Prague Botanical Garden on annual butterfly event.

Butterfly Butterfly

Photo of a week 11

I somewhat failed last week to take a photo because I was too busy with other things. However to stay on track I decided to publish about one month old photo from Charles bridge in Prague.

Gull on Vltava

Photo of a week 10

Tenth week and I'm still in. Honestly I did not expect to keep up that long. Last week there was a carneval at Žižkov (part of Prague) and the picture comes from it.

Žižkov carneval

Photo of a week 9

Next week is over and it's time to show another picture. Today I've decided for indoors photo, what is something I usually don't take, but here it is.

Pavlov wines

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