Imprex 2.0 image processing Experiences/Tutorial (impacting PQ seriously)

[Nice Monkey]

For people interested in a personal view and experiences with Imprex 2.0 on Q10 Pro. All testing done using a standard HD TV (no 4K UHD up-scaling).

Some may have problems finding the Imprex engine settings as they are not to be found anywhere in the main menu. When playing a video go to settings and next advanced options. This is put here as a video must be played to apply live PQ processing features (split screen to see the effect is available).

1) First of all "Image Processing" is manipulation of source video material to improve the PQ as perceived by the viewer. What is perceived by an individual is not necessarily the best possible PQ as measured by a professional (or perceived by other persons).
2) Most (if not all) high end TV-sets and Projectors have their own "Image Processing" features each with a nice brand specific label. It is questionable if Imprex 2.0 is better than the features included with your (expensive) TV? Using both concurrently can (and probably will) have negative side-effects. Also a Receiver/Amplifier in the chain may have an active role and do up-scaling or other types of image processing. You will need to play around with each component to judge the effects of each variable yourself. Find out which component does the best job for you with your specific setup. After changing a main component you will need to redo this piece of essential homework.
3) PQ improvement is primarily meant to compensate for suboptimal source material. There are many features tackling individual flaws of source material. It is my experience that with HQ source material like uncompressed Blu Rays and even quality uncompressed DVD more harm is done than improvement  achieved. When someone uses a lot of heavily compressed (re-encoded) AVI and MKV material then the positive effect is probably a lot higher.
4) I am playing almost exclusively DVD and BD media in1:1 ISO format. But as a classic movie fan the media available is not always top notch. For most movies I prefer the Imprex OFF setting (hence my default). Also most PQ improvement settings on my TV are default OFF. Notable exceptions are movies with bad contrast or a high level of noise which are the most commonly found drawbacks on classic movie BD's. Specifically the noise reduction of Imprex 2.0 works remarkably well. Contrast problems are probably slightly better handled by my TV but the difference is marginal (but Q10 PQ settings are easier to change in-flight). For heavily compressed material the MPEG artifact reduction and Natural Motion options were observed to occasionally improve PQ with my setup.

By default Imprex 2.0 is ON with a variety of features applied in various degrees. The impact of these settings on PQ are not to be ignored as they are clearly visible. Defaults on your TV and Q10 Pro is probably not what you may like best:
- A good start is turning them all off (both TV and Player) and adjusting standard picture settings optimally using a reference image or test disk first. Normally you do this on your TV directly. Only if there are differences between different HDMI sources you may need to tweak player picture settings individually.
- Next start re-enabling feature by feature. Use material which is representative for your average viewing. When in doubt don't enable that specific feature with default on. You may be tempted to keep settings at the LOW level but in general I can't recommend doing so. It won't bring clear improvements when really needed and instead just degrades the PQ all the time when it is not needed.
- Last but not least teach yourself which setting(s) to apply to compensate for specific flaws per viewing. That way you will be getting the best from Imprex 2.0. You very probably benefit the most from the individual HIGH settings for this purpose.

I read that the next FW will enhance Imprex 2.0 in some way(s). Most of this tutorial will remain valid also if the quality and/or functionality is enhanced.
With the current implementation I am not really impressed and having it by default ON was for me the wrong start.

Comments , other views and additions are more than welcome.

If there is serious interest I might add observations and testing recommendations for each Imprex 2.0 parameter available.

[Djinn]

Comments , other views and additions are more than welcome.

There are some people in the official KODI forum claiming that the Imprex Engine cannot be disabled entirely, that is, the HiMedia is ALWAYS POSTPROCESSING the image. In order to see a "natural image", you cannot just disable the Engine, you must adjust the Imprex values to a particular setting. According to one user:

BigPines Wrote:
One thing I should point out is that the external player is always processing the image even after disabling Imprex. I found that both whites and blacks are crushed even with Imprex off and image settings set to standard. So unfortunately, there is no true pass-through available on the device as it is always altering the image. I reported this problem to Himedia during the pre-production testing and I have confirmed the problem exists on the production hardware as well. The work-around I found was to turn off all Imprex options and set Brightness to 66 and Contrast to 43. This eliminates crushing on both blacks and whites. I used a test pattern from Digital Video Essentials to confirm this."

Another user has confirmed that this bug? is still present on firmware 1.0.7:

I can confirm that the Q10 Pro even with the latest 1.0.7 firmware ((late august 2016)) is manipulating the picture.
Crushing my blacks, giving less pop to colors, more color banding. As mentioned, Q10 needs to boost up the brightness settings and reduce on contrast. But not as much as brightness 66 and contrast 43 on my system.
I need brightness to about 55, to reveal details in the dark, but the overall picture then gets a bit washed out and flat.

The original discussion can be found HERE.

I'm not an A/V expert, not even I've calibrated my TV, so I'd like to know what do you think about this and if you've noticed this unwanted effect. May this be considered a (serious) bug?

Thanks

[Nice Monkey]

Next to Imprex choosing the colorspace / HDR is far from trivial. That could be the source too? It is very bad that no information is given here.

One is tempted to go for 10-bit but with my TV that does not work out well (1080P with deep color at even 12-bit). But I play DVD/ BD source material which all is 8-bit.

Now using HDR set to Other that works reasonable well. Now waiting for the 1.0.7 fixes as 1.0.6 worked better for me.

[Djinn]

Thanks NiceMonkey. We need somebody confirms this bug (if exists). I suppose that those users know what are they talking about...

Futeko admin, could you tell us something about this? Do HiMedia know this issue and are they going to fix it? Remember that one expert user told in that forum that this bug was present on pre-production and production samples:

I reported this problem to Himedia during the pre-production testing and I have confirmed the problem exists on the production hardware as well.

Thanks

[futeko.com]

Thanks NiceMonkey. We need somebody confirms this bug (if exists). I suppose that those users know what are they talking about...

Futeko admin, could you tell us something about this? Do HiMedia know this issue and are they going to fix it? Remember that one expert user told in that forum that this bug was present on pre-production and production samples:

I reported this problem to Himedia during the pre-production testing and I have confirmed the problem exists on the production hardware as well.

Thanks

There are a large number of Q5/Q10 Pro with customers and this problem has not been widely reported.  My personal opinion is that it's probably caused by something other than an inability to disable imprex. The lack of documentation surrounding HDR and colorspace modes makes diagnosing a marginal problem like perceived crushed blacks very difficult. As Nice Monkey says, it could be something to do with a choice of suboptimal colorspace for this person's hardware.

The lack of documentation is something we have repeatedly requested that HiMedia resolve. Unfortunately the total lack of detailed documentation has become the standard situation for Chinese media players. It's an area in which HiMedia could further elevate themselves above the rest.

HiMedia are doing constant work on Imprex and PQ in Q5/Q10 Pro but this specific problem needs more user reports and to be reproducible before it can be considered a 'bug'.

[Djinn]

Thanks NiceMonkey. We need somebody confirms this bug (if exists). I suppose that those users know what are they talking about...

Futeko admin, could you tell us something about this? Do HiMedia know this issue and are they going to fix it? Remember that one expert user told in that forum that this bug was present on pre-production and production samples:

I reported this problem to Himedia during the pre-production testing and I have confirmed the problem exists on the production hardware as well.

Thanks

There are a large number of Q5/Q10 Pro with customers and this problem has not been widely reported.  My personal opinion is that it's probably caused by something other than an inability to disable imprex. The lack of documentation surrounding HDR and colorspace modes makes diagnosing a marginal problem like perceived crushed blacks very difficult. As Nice Monkey says, it could be something to do with a choice of suboptimal colorspace for this person's hardware.

The lack of documentation is something we have repeatedly requested that HiMedia resolve. Unfortunately the total lack of detailed documentation has become the standard situation for Chinese media players. It's an area in which HiMedia could further elevate themselves above the rest.

HiMedia are doing constant work on Imprex and PQ in Q5/Q10 Pro but this specific problem needs more user reports and to be reproducible before it can be considered a 'bug'.

Thank you .. I will be watching the KODI forum and if I see another user complaining about this, I will let you know. Maybe it's too early to consider this issue a bug, but more documentation from HiMedia would be welcome.

When you buy a 'non-chinese' product, like a Panasonic, Sony or Philips Blu-ray, you have all modes of image enhancement documented in the User's Manual and everything works as expected. If HiMedia wants to be the #1 in multimedia players, beating the competition, this is a MUST. The product must work as expected, or at least, as documented in the manual, detailing cases with conflicts between HDR and colorspaces, if so.

[trykkertor]

How do I disable the Imprex engine on Q10?

[OlivierQC]

Good morning,


the answer is available here :
http://forum.kodi.tv/showthread.php?tid=265888

Tips and Tricks:

Don't care for Imprex engine? Here's how to disable it and get proper unprocessed PQ...

(2016-04-21 20:54)BigPines Wrote: 
One thing I should point out is that the external player is always processing the image even after disabling Imprex. I found that both whites and blacks are crushed even with Imprex off and image settings set to standard. So unfortunately, there is no true pass-through available on the device as it is always altering the image. I reported this problem to Himedia during the pre-production testing and I have confirmed the problem exists on the production hardware as well. The work-around I found was to turn off all Imprex options and set Brightness to 66 and Contrast to 43. This eliminates crushing on both blacks and whites. I used a test pattern from Digital Video Essentials to confirm this.

see you

[hdmkv]

I just revised "disable" to "minimize" effects of Imprex. I think this would be considered a bug as if there's an option included to turn off Imprex, but PQ is still being 'processed', then it didn't turn off.

Many users want PQ in = PQ out (as is) without any processing at all, so HiMedia should allow ability to completely disable Imprex. This is same as what CloudMedia does w/Popcorn Hour players and VXP processing I believe, or the Darbee processor on Oppo BD players that have it.

[Eriol]

Many users want PQ in = PQ out (as is) without any processing at all

+1
Imprex off makes the picture pretty dark by default so I need to play with brightness and contrast to get a more natural picture. Basically I would like to have picture come out from the box as is and setup my picture related settings on my tv which gives me much more detailed and subtle options.

[domifer]

+2

[ceaca]

Imprex engine  2 it is not working at all as it should be.the new settings are old Q10 quad.
I want imprex 2 to be fully on 10pro.
natural image ...it is  a taste...on ,off---but i buyed for this engine

Sorry, very bad english.

[Djinn]

I think this would be considered a bug as if there's an option included to turn off Imprex, but PQ is still being 'processed', then it didn't turn off.

+3, I totally agree. If HiMedia have included an option in the UI to disable the Imprex Engine, then that option should work as expected. In other words, if Imprex Mode is set to 'OFF',  the displayed image should be exactly the source. Users also want to get a natural image without any enhancement and, furthermore, I'm pretty sure this is the most wanted mode.

[trykkertor]

+4
If this option to deactivate Imprex doesn't come around, my Q10 will be degraded to a NAS, or simply sold again.
The image is not up to my standards with the crushing of darks and brights, the colorbanding, and lack of pop in the picture.

I suspect my old PlayOn MiniHD not to fuck up the image, as files from this unit is so very much better on my setup.
I've tried the Q10 Pro 4k both to my high end JS9500 screen in 4k, and to my  mid-end 1080p projector from Sony, and the PlayOn beats the Q10 every time on picture quality.

[EazyVG]

Hi everybody. I am a new user and decided to repost my reply from Kodi forum here:

Tips and Tricks:

    Q5/Q10 Pro Output Info Diagnostic Tool by @pcristi
    See @OlivierQC's helpful video tutorials here.
    Don't care for Imprex engine? Here's how to minimize its effects and get better blacks & whites...

        (2016-04-21 20:54)BigPines Wrote: 
        One thing I should point out is that the external player is always processing the image even after disabling Imprex. I found that both whites and blacks are crushed even with Imprex off and image settings set to standard. So unfortunately, there is no true pass-through available on the device as it is always altering the image. I reported this problem to Himedia during the pre-production testing and I have confirmed the problem exists on the production hardware as well. The work-around I found was to turn off all Imprex options and set Brightness to 66 and Contrast to 43. This eliminates crushing on both blacks and whites. I used a test pattern from Digital Video Essentials to confirm this.

Unless it is already mentioned but not on the first page - you can actually turn Imprex OFF. Briefly my setup is 4K HDR10 (Sammy KS8000 EU model) + AV Receiver (Denon X1300W). First you go to Settings->Advanced and select "SDR" under "TV HDR Mode", then launch a movie and Turn Off Impex, then head back to "Advance Options" and select either "Auto" or "HDR10" if your TV supports it. I have compared the scenes with my older HTPC and indeed there is no processing happening, about 99% is turned off. Imprex is definitely no go, too much effects and post-processing.

The only issue I am having, a major one, is actually with the HDR content. I have tried quite a few options and it seems that the current Q10 Pro's "Video Color Space & HDMI deep color" is not working properly. I have, as of today, latest custom 1.07 firmware and set at 2160/60p with YcbCr420 10Bit" (UHD content produced in 4:2:0). When I compare Life Of Pie (HDR 10bit HEVC 24fps) launched on TV via USB (or external HDD) to how Q10 Pro reproduces via HiMediaPlayer, you can see clearly that the dark scenes are not dar enough, colours are not vivid and there is major greyishness present as if it is 8bit source. I have tried many-many settings and combos and it is no go. I hope the newer firmware will solve this issue soonest.

The other two major issue, perhaps related with Kodi Android version (as I was using it on a HTPC Linux built) are:
- No settings for DTS-HD and Dolby TrueHD in Kodi - thus, they do not reproduce correctly. Only correctly when played via Himedia Wrapper from inside Kodi, including the Dolby Atmos.
- It seems that as of now HEVC 10-bit & HDR is not fully supported by Kodi 16.1 - right?
- And, unlike HiMediaPlayer, the Kodi built-in player has issues with FPS matching - think all play at 60fps.