gimp

HDMI colour space – a crooked bastard!

Thursday, November 7th, 2013 | Gadgets, Insights, Misc, Tech-savvy | No Comments

One would think that hooking up a device to a TV using a HDMI cable would automagically result in a perfect picture. Digital, 1080p full HD, state of the art, out-of-the-box. That’s not true. I recently encountered shitty display quality problems that originated from a faulty HDMI setup.

First, the problem: sometimes black was more like a gray matter, sometimes dark details simply vanished into sludge. I did hate my telly so much for its shitty display quality that I sold it for a few dimes and got myself a new one. But guess what, the problem persisted…

After more investigation on the matter I came across the fact, that there are different colour ranges in different HDMI standards and one handles the range from e.g. black to white from 0 to 255, the other from 16 to 235. This made me think. In case I had a mismatch of these standards, and let’s say my media player sends a lot of dark gray values that range from 0 to 16 and the receiver simply omits all these information and starts with pure black at 16, it’s natural my dark details got lost. Or, the other way around, my media player starts at 16 with pure black while my telly thinks that 16 already is a dark gray, as it starts with black being 0.

So, sending full range and displaying limited range will result in dark areas that are to light and light areas that are to dark.

Sending limited range and displaying full range will underexpose blacks and overexpose whites.

Here is an example (I simply altered the source and target colour ranges with Gimp):

Nature LimitedFull Nature Original Nature FullLimited

The differences may seem subtle (or YOUR display isn’t properly calibrated), but believe me, I love to crawl in dark dungeons on my PS3 or watch horror flicks that make heavy use of the darker parts of the colour palette. My telly looked like the picture to the right all the time and it drove me to sell it for “bad black levels” (just compare the tree’s trunk in the pictures and you will see the difference). Silly me. A perfect gradient illustrates the problem even more:

Gradient LimitedFull Gradient Original Gradient FullLimited

Now, that I have my systems set up right I enjoy using it so much more than before. So, give setting up your expensive home cinema a try, it doesn’t make sense to spend thousands of bucks on the equip and not setting it up properly.

As far as I understand the problem, as long as you have the sending and the receiving device configured the same you are good to go.

One last thought: I hate all the fancy tech shit becoming more and more “easy” to set up yet the problems that come along constantly increase. I never experienced problems with an old VCR or a Super Nintendo – that’s what I call “plug’n’play” 🙂 To set up a modern home entertainment system you need to really dig into it to do it right. Maybe I should look at it from a Dark Souls perspective. It’s a pain in the arse, but as soon as you’re done it’s very very rewarding.

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A Studio Ghibli homage

Thursday, February 2nd, 2012 | Activities, Misc, Movies | 1 Comment

Today I invited Totoro to stay.

Ever since we moved into our “new” flat a few years ago we could not decide what to do with our living room walls. I suggested that we could try to draw the Studio Ghibli logo – namely Totoro – next to the TV. The other side of the telly got decorated with the beautiful postcards that come with the German Blu-ray edition of Arietty and Laputa. Now I feel like a true fanboy 🙂

And this is how I will enjoy my films from now on:

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¡Hola Mexico!   aka   Our 2011 Xmas Retreat

Tuesday, January 24th, 2012 | Activities, Photography | 2 Comments

Mexico – a great place to escape the Xmas stress and general greyness of Germany in the winter. It’s almost unbelievable how many colours you miss getting out of a plane from Mexico … just look out of your window when you’re done flicking through these sample shots. Enjoy.

Regarding the post-processing – I feel like a cook that just learned about salt and pepper, so he applies a lot to each meal. Right now I like the style of punchy colours and unsharp masked pictures but I already feel that I am getting tired of these dishes … I’d like to experiment with thyme, oregano, parsley and what else the kitchen (RawTherapy/GIMP) has to offer. So much to learn …

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Turmhotel: impressions of a dying building

Monday, December 12th, 2011 | Activities, Photography | 5 Comments

The Turmhotel has been around for as long as I can remember. I heard stories of the cinema (Metropolis?) that stood here before. Fun fact: the same guy who blew up the old cinema in 19xx (help needed) is responsible for blowing up the Turmhotel on December 18th this year.

Here are some impressions of the building a few days before its planned destruction. Black and white high-contrast images to emphasize the abuse the bulldozers did already. It’s spooky to see the violated remains of a building that once hosted a vivid shopping centre and – of course – the infamous hotel. Even though it is considered an unsightly building it’s still the landmark that represented the centre of town for decades. I will miss it.

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Determining poly image map coordinates

Thursday, September 9th, 2010 | (X)HTML/CSS, Quirks, Tech-savvy | No Comments

I am currently working on a “self inflicted” project where I record all my old tapes. Expect a post about this soon. Doing so I took pictures of my tapes, linking the displayed tapes to their corresponding playlist. As this can result in non-rectangular shapes I am using poly image maps, but determining the coordinates became a drag, as my ancient Photoshop 5.5 only displays one x/y coordinate at a time. Writing this post I dl the current GIMP, because I want to know whether this tool lets you get a list of all coordinates of a polygon at once.

Anyway, googling I found Eleomap, a pretty neat online tool that lets you enter a link to a web-accessible picture (no upload supported) and draw your shapes right onto the picture. It supports multiple shapes and multiple maps. You need to get used to the usage a little bit (RTFM), but after that you will be able to get your poly coordinates in no time.

P.S. The GIMP dl just finished, I installed it, and – how could it be any different – it provides a brilliant image map tool (Filters -> Web -> Imagemap) – how kewl is that?

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