A remarkable absence of features, support or even mention of RAW photography and DNG format in +Google Photos

– Upload RAW DNG photos on Wi-Fi by default, just like videos.

Google drive backend is already capable of rendering and even editing pictures stored in proprietary camera RAW and DNG, so that's a missed opportunity now that Android smartphones are able to shoot in DNG+JPEG.


Picture this: A fresh approach to Photos

Source post on Google+

Great study from +Gary Sims​ on +Android Authority​!


Fact or Fiction: Android apps only use one CPU core
We have had multi-core processors in our PCs for over a decade, and today they are considered the norm. At first it was dual-core, then quad-core, and today companies like Intel and AMD offer high end desktop processors with 6 or even 8 cores. Smartphone processors have a similar history. Dual-core energy efficient processors from ARM arrived about 5 years ago, and since then we have seen the release of ARM based 4, 6 and 8 core processors. Howev…

Source post on Google+

This is a 3D visualization of Nexus 10 display color response compared to a reference Gamma 2.2, Rec.709 color space

Nexus 10 display gamut is small, so it doesn't cover the whole cube.
Due to the nature of its the blue primary, some colors would be outside the cube so I clipped them in this graph.

It's also the demo of a new tool that will help me greatly visualize measurement, calibration and correction data 🙂

#supercurioBlog #color #display #measurements #development


In Album 2015-05-16

Source post on Google+

Experimenting with tri-dimensional interpolation methods for sparse data:

This one is not fit for the job it seems, especially since the input data will often be only 6x6x6.
I'm probably gonna need a more linear than cubic interpolator here.

That's Apache Commons Math TricubicInterpolator, comparing 64x64x64 reference output with interpolated input from 2x2x2 to 16x16x16 sizes.

#supercurioBlog #color #development


In Album 2015-05-13

Source post on Google+

I started implementing an Android system driver using the GPU for color correction and calibration

I already hit some limitations here and there (being well known by game developers) but am confident in the possibility to find solutions to get satisfying performance and results on all OpenGL ES 3.0 devices and most GL ES 2.0 ones as well.

And here's something to show you!
In my last post, I mentioned how exciting it was to not be limited to 8-bit per channel precision, which is a tough compromise when correcting displays because it means you introduce banding.
Yesterday's post: https://plus.google.com/+supercurioFrancoisSimond/posts/Dv7JzLAP5ev

In these graphs, there's a Nexus 5 running the driver in development which naively divides RGB values per 10 which makes the output much darker.
At 100% brightness: it hits 3 cd/m², for a contrast ratio as low as 10:1.

See for yourself the result of changing colors on 8-bit, vs what can be done by creating those intermediary tones that the display hardware, a 8-bit panel cannot produce.

Image 1 and 3: 8-bit
Image 2 and 4: same 8-bit, same content but but simulating the intermediary colors using GPU post-processing.

I didn't expect such extraordinary results, but it's real 🙂

#supercurioBlog #calibration #display #color #development


In Album Better than 8-bit per channel precision

Source post on Google+

Some facts after a quick analysis of both +HTC #ONEm9 and +LG Mobile Global #LGG4 produced DNG

– Both lack flat-field correction
– Both provide incomplete matrix-only color profiling: no DCP
– Neither use compression
– HTC One M9 DNG is 10 bit stored in 16bit uncompressed data: 39MB per 20 Mpixel image.
– LG G4 DNG is 10 bit stored uncompressed, 20MB per 16 Mpixel image
– Both have non-optimal noise profiling settings: HTC One M9 set noise reduction too high and LG G4 lacks noise profiling entierly.

Notes on flat-field correction:
Mobile camera modules require such correction to correct both vignetting and color cast (like pink spot / greenish or blueish corners).
HTC One M9 requires less correction than the LG G4.
It is only possible to compensate for light fall-off, in RAW image editors, not color cast.
As a result, the color cast in corners is essentially non-fixable.

Attached: the #LGG4 DNG sample provided by +Colby Brown rendered in Lightroom with only modification an increased contrast and exposure slightly, to make both vignetting and color cast more obvious.

The least I can say is that there's room for improvement, both DNG implementation being non-optimized and incomplete.

#supercurioBlog #LG #DNG #color #camera #calibration


Source post on Google+