Sony mobile made progress with their displays hardware with the Z2. Their previous panels had sub-standard viewing angles with no benefit in contrast ratio

So what they have now is a decent IPS panel, using a blue led as backlight plus phosphors to alter the wave-lengths generated, which results in a wide gamut display with satisfying power efficiency.

Conceptually, having a wider gamut than the common Rec.709 and sRGB is interesting because the human eye can perceive colors so much more intense than sRGB gamut, around in an approximate fashion since CRT monitors.

But let's hold back here: what's a display?
It's a rendering device, reproducing colors previously encoded into numbers or voltages in the old days.

So a good display is what reproduces the colors as they're supposed to. Typically, as the graphic artist intended or as a camera encoded them from what hit its sensor.

As a result what's desirable is both a camera (or artist) and the display agreeing on how to record, encode and present again those colors.
Well that's the basics of display calibration.

Sony has an interesting technology, allowing to reproduce more intense colors and most people craves those, they produce emotions.
But today's content usually are not encoded in a way that can represent those colors intensities.
It's just not here anymore!
Colors that are in nature, that also can be perceived by your eyes but can't be stored in the mathematical encoding of sRGB (computers) or Rec.709 (HDTV) gamut (both share the same)

Sony has this display on the Z2 but unfortunately didn't implement anything to display images according to how their colors are encoded.
Instead, they'll simply let the display stretch colors intensities, and also show the wrong color hues because the Z2 panel RGB primaries are not aligned with sRGB gamut.

That's the typical issue when you're lacking color management.
Instead of converting a color space to another, you're not processing anything and show un-corrected colors.

And then here comes the marketing department, who made this page that totally baffles me by the quantity of bulcrap it contains.
It's pretty much feeding readers lies about color reproduction and accuracy to convince them the oversight is actually not only a good thing, but also right and accurate.

With IPS technology, the Xperia Z2 offers an improved viewing angle. So you get super sharp images and accurate colours, no matter which angle you’re looking at your device from.

All things considered, if you compare to the Xperia Z or Z1 yes the colors are indeed more accurate.
It doesn't make Z2 display a color-accurate display tho.

TRILUMINOS™ technology uses LEDs, which emit purer reds and greens, creating a brighter and more uniform light that captures the true colours of the source. From lush landscapes, to natural skin tones – Sony delivers a significantly wider colour range. So you can view every moment in astonishingly authentic colour and breathtaking quality.

Wait wait wait.
Sony, are you really saying that the display is actually a camera? capturing the true colours of the source.
A camera captures colors. Not a display.
See, that's the rhetoric used to pretend that the display knows (!) what were the colors when captured, and thus can reproduce them accurately.
Needless to say, it's complete nonsense.
Then continuing on, Sony tells you the display renders authentic colour

Science check: that's absolutely wrong. Remember I told you sRGB gamut is far from covering what your eyes can perceive. So if your camera records image in sRGB, those intense colors are gone. Like an intense red will be recorded as a less intense red, that's all.
So how could a display know what the authentic colors were.
Was the display here with you? What does that even means.
No, the display will only render colors encoded to be a specific tone and intensity to another color. Because.
Of course it won't be the real color, unless you get 16.7 millions against one lucky, assuming this color was even part of Z2 reproducible colors.

This new innovation combines red and green phosphor with blue LEDs and customised colour filters to produce a brighter and more uniform light. Capturing true colours without the risk of oversaturation.

The marketing here using a formulation optimized to trigger the placebo effect. And believe me placebo (at any price point) sells with almost no limit when it's about display or sound quality.
Even medicine. But people rightfully take this a little bit more seriously 🙂
So yes colors are over-saturated, it's a measurable fact.
But maybe if Sony tells you they're not you'll believe them. No harm trying right?

The Intelligent Image Enhancer reproduces the vividness of the image in its original colour

Again, same thing. Boosting colors not as selectively as described here won't get you anywhere near the original color.
More nonsense.

If you actually watch video content today on a Z2, the color processing might make you uncomfortable.
They take standard content, stretch colors to the wide gamut of the display, and on top of that boost colors some more.
The result looks simply ridiculous, even on skin tone which is a big no-no.

But well, this is Sony's marketing so nothing new here, I think it's a tradition of theirs for consumer products.

Personally, I really don't like abusive usage of "color accuracy" mentions.
That's why I'm working on measurement tools allowing to verify claims, because color is actually a science.
Also, there's a lot of progress to make thanks to wider gamut displays.
Those are undoubtedly the future, but today's ridicule usage made of them mostly discredits their benefits.

#supercurioBlog #color #display #critic #marketing

Xperia™ Z2
Sony’s best phone camera is the Xperia Z2 which features a 20.7 MP camera and 4K video recording – all packaged inside a gorgeous aluminum frame.

Source post on Google+

Calibrating a computer monitor via 17 grayscale points only, and manually?

Wow, my calibration algorithm works automatically and with 256 points instead.
That means correcting every single color in the grayscale instead of the usual grand interpolation approximation as demonstrated here.
I also notice that their automatic calibration starts at $299.

#supercurioBlog #display #color #calibration

Direct Display Control, AutoCal, And PC Client 3

Source post on Google+

Continuing my personal calibration algorithm project during this week end:

I got the black point calculations right this time!
This one wasn't so easy to write and required some silence to boot 🙂

Now it works just as expected and allows to generate a XYZ black point target:
– from a XYZ input (measured) blackpoint
– for a defined RGB colorspace
– for target white point
– with two parameters allowing to specify how much the black point color should stick to the white point color or to the input black point XYZ color, and another setting the balance between channel clipping and clipping protection.

Coding for my own still feels different (relaxing) compared to coding for work.
Phew! Alright, I wasn't sure it would happen.

#supercurioBlog #calibration #color

Source post on Google+

While testing some changes in the color science math of my calibration and measurement program, I took a look at my Galaxy S4 I9500 set to Movie Mode, at 100% brightness

This is is the mode described as color-accurate here:

The Galaxy S4 Movie Mode provides very nice, pleasing, and accurate colors and picture quality
Movie Mode, Very Good Calibration
Very Good Images, Photos and Videos have very good color and accurate contrast

Based on those high precision measurements, I beg to differ. My rating would be poor or very poor.
Color manipulations are so wrongly done that some secondaries (cyan and yellow) are not even in line with primaries!
Well, this is an example of what happens when using not enough data to cherry-pick evidence that suit your established conclusion.

That's the reason why I'm committed to provide display analysis software and training to any reviewer interested.
The current source , considered as reference is not as good as it should, also possibly biased based on the fact its conclusions doesn't even match the data published.

Anyway. Yay, the new code works great 🙂

#supercurioBlog #display #color #measurements #critic


In Album Galaxy S4 Movie Mode

Source post on Google+