VPX(8) - New features - LUTs and Brightness, contrast, saturation & temperature curve effect

browj2 wrote on 6/3/2016, 4:35 PM

Hi,

Magix added a couple of nice features into VPX on the Effects, Video effects, Brightness/Contrast screen, but the manual is short on detail.

The Brightness, contrast, saturation & temperature curve effect allows you to modify the parameters by modifying the curve and there are a few modes to do so. Probably it is best to put up the measuring meters and take care to not overdo anything. RGB and individual R, G, and B channels can be modified individually and each one has a modifiable curve. The mode can be changed to use Bézier handles.

The other addition is a button for "Load lookup table" or LUT. This is not documented and I had to do some research to find out what this was. i downloaded a couple of free LUTs and loaded one. Unfortunately there are two problems that I have found:

  1. The name of the table always seems to be "generate by resolve"
  2. Clicking on the button always goes to the default folder "C:\ProgramData\MAGIX\Video_Pro_X8" and that is not where I put my LUTs. I put them in "B:\Documents\MAGIX\Video Pro X\LUTs."

Here are the screen shots (my preview monitor is not shown as it is on a second screen.

I would like to know more about how to properly use LUTs. Does anyone have a good reference?

We have Magix Movie Looks presets and Magix Bullet Quick Looks (a very condensed version), and I have Pixelan FilmTouch 2 Pro which contains extensive colour looks or colour grading and a wide array of tools to modify the presets. Are these not all similar to LUTs?

Thanks,

 

 

Last changed by browj2 on 6/3/2016, 4:35 PM, changed a total of 1 times.

John C.B.

Desktop System - Windows 10 Home 1903; 16Gb RAM; i7 CPU 860@2.80Gz; ATI Radeon HD5770 w1GB; SSD 500GB, HD 2TB; others 1.5TB, 3TB, 500GB, 4TB, 5TB, 6TB; dual monitors - 27" main, 25" secondary; Casio WK-225 piano keyboard; M-Audio M-Track USB mixer; Notebook - Microsoft Surface Pro 4, i5, 8 GB RAM, 256 SSD, W10 Pro 1903

Comments

johnebaker wrote on 6/4/2016, 1:26 AM

Hi John CB

I have not experimented with the LUT's yet, however AFAICS you cannot adjust the individual RGB curves until you make an adjustment on the overall brightness curve first to reveal the underlying RGB curves.

Have you seen this video in LUTs -

What I do miss is a pipette sampler which will tell me the RGB composition of the colour where sample as shown below from PSP X7.

Do you have any success with the Shot Match feature - so far it is producing weird colours shifts when I try to match two different images, particularly with snow scenes, one of which has a distinct blue cast..

HTH

John EB

Last changed by johnebaker on 6/4/2016, 1:26 AM, changed a total of 1 times.

Lateral thinking can get things done!

VPX, MEP Premium, MEP 2016, and earlier versions, Music Maker Premium, Music Maker 2016, 2015.

Running Windows 10 64bit on Intel i7-8700K 3.2 GHz, 16Gb RAM, 1Tb + 2 x 2Tb internal HDD + 60Gb internal SSD, + 6 x 2Tb ext HDDs, Sony FDR-AX53 Video camera, Contour HD 1080 and Sony HDR-AS30V Sports cams.

browj2 wrote on 6/5/2016, 5:55 PM

Hi John EB,

Thanks for the video link, I had not seen it.

Since my cameras do not use log exposure, then the use for LUTs gets down to Emulating film and Looks.

You mentioned in my bugs post that there is some Gernam text on the Brightness/Contrast screen. I don't see any, but I do under keyframing for the Shot match screen - at the bottom "angewendet."

For the Brightness curve, I was able to modify one of the individual colour lines without first making an adjustment on the overall brightness curve. Click on the pop down button beside Channel RGB and you can select a colour.

You didn't attach the sample from PSP X7 showing the pipette sampler, but I know what you mean. None of the pipette samplers in VPX have a readout of the RGB composition. There is a pipette sampler under Color for White balance/White point, and two pipettes under Shot match, but no readout.

Some of the NewBlue tools, like Color Fixer Pro have pipettes that can sample colours, but the image is too small for any precision. Select a point and the colour above the pipette will take on the sampled point. Click on this colour button and the Color screen opens showing the HSL and RGB values of the sampled point. But how would knowing this help with the colour correction tools that we have? This is the closest that I could find that at least provides the information in VPX.

For Shot match, I have only made a couple of tests, both in the snow. In one, the white balance was way off and the snow was bluish. The other was fine. Shot match corrected the snow colour to match the good image. However, when I tried with another source image, one that was a close up (of Bernadette with a red vest), the snow ended up too orange/yellow, and the vest heavily saturated bright red. Doing an enhance manually on the snow, corrected the snow colour, but the red was still too saturated and my wife's black coat tinged purplish. Doing an additional enhancement on the red vest gave blotched/posterized red vest. A third enhance using the dog's black boots and my wife's coat reduced the purplish tinge somewhat.

My conclusion here is that the images have to be more similar in nature as per the manual, so a wide angle shot and a closeup were really not compatible for this method.

Here are the images:

Source:

Target:

Result 1:

Source 2:

Result 2 - automatic:

Result 2a - manual enhancement on snow:

Result 2b - manual enhancement on dog's vest

I'll hunt down and try out one where from one frame to the next the colour shifted dramatically, with the highlights suddenly becoming very yellowish.

Last changed by browj2 on 6/5/2016, 5:55 PM, changed a total of 1 times.

John C.B.

Desktop System - Windows 10 Home 1903; 16Gb RAM; i7 CPU 860@2.80Gz; ATI Radeon HD5770 w1GB; SSD 500GB, HD 2TB; others 1.5TB, 3TB, 500GB, 4TB, 5TB, 6TB; dual monitors - 27" main, 25" secondary; Casio WK-225 piano keyboard; M-Audio M-Track USB mixer; Notebook - Microsoft Surface Pro 4, i5, 8 GB RAM, 256 SSD, W10 Pro 1903

johnebaker wrote on 6/6/2016, 2:38 AM

Hi John CB

. . . . some Gernam text on the Brightness/Contrast screen. I don't see any . . .

You are correct, I was going from memory which effects I had been playing with and found the German text - Shot Match was one of them.

. . . . Click on the pop down button beside Channel RGB and you can select a colour. . . . .

This I do however as when I select the curve it picks the white line not the selected colour, also the dropdown goes blank when I do get the single colour curve as shown below

. . . .the Color screen opens showing the HSL and RGB values of the sampled point. But how would knowing this help with the colour correction tools that we have? . . . .

I use colour correction by numbers using curves in PSP.  The same principle can be applied to video if you know your starting values for RGB in VPX.

Essentially you ensure that all the neutral colours eg black, mid greys and whites are correctly balanced for R, G and B then all the other colours automatically become corrected - I got this from an old book - Professional Photoshop 5 by Dan Margulis - and used to teach the technique in my Digital Photography classes. 

If I had the numbers from the video then I could add points to the curve then use the indicated input boxes to  enter the correction numbers.

 

Here is a before and after example of a still image corrected by this method

 

As you can see the original has a distinct red cast.

Shot match

You are getting the same results as I did with snow pictures - I was testing matching tose woth a blue cast to other correct ones - as you say the images have to be a very close match in terms of colour content.

John EB

Last changed by johnebaker on 6/6/2016, 2:38 AM, changed a total of 1 times.

Lateral thinking can get things done!

VPX, MEP Premium, MEP 2016, and earlier versions, Music Maker Premium, Music Maker 2016, 2015.

Running Windows 10 64bit on Intel i7-8700K 3.2 GHz, 16Gb RAM, 1Tb + 2 x 2Tb internal HDD + 60Gb internal SSD, + 6 x 2Tb ext HDDs, Sony FDR-AX53 Video camera, Contour HD 1080 and Sony HDR-AS30V Sports cams.

browj2 wrote on 6/16/2016, 10:47 AM

Hi John EB,

I can't reproduce your problem. If I first change the colour to red then select the line, the red line is selected and moved and Red is still showing in the dropdown.

I am still lost on most of this despite a lot of reading.

"Essentially you ensure that all the neutral colours eg black, mid greys and whites are correctly balanced for R, G and B then all the other colours automatically become corrected..."

How do you ensure that the neutral colours are correctly balanced for RGB?

I took a look at the Virtual Dub plugin - Gradation curves (there is a 64bit version) and read through the tutorial.

I also found an ON1 tutorial that seems quite useful for the work process of colour grading using filters. I have the ON1 Free effects 10 (it was free) and Perfect Effects 9 that came with PSP Ultimate X7 or X8. But trying to translate that into video, I got lost with the B&W part and the blending.

I have also been looking at Pixelan FilmTouch 2.0 Pro. It is important to read the tips to understand how to use the sliders. It would be nice if there were instruments to go along with this to see what happens. The effect stays in the plugin so there is no preview in the VPX instruments. With the VirtualDub gradation plugin, changes are previewed in VPX and in the VPX instruments.

 

 

Last changed by browj2 on 6/16/2016, 10:47 AM, changed a total of 1 times.

John C.B.

Desktop System - Windows 10 Home 1903; 16Gb RAM; i7 CPU 860@2.80Gz; ATI Radeon HD5770 w1GB; SSD 500GB, HD 2TB; others 1.5TB, 3TB, 500GB, 4TB, 5TB, 6TB; dual monitors - 27" main, 25" secondary; Casio WK-225 piano keyboard; M-Audio M-Track USB mixer; Notebook - Microsoft Surface Pro 4, i5, 8 GB RAM, 256 SSD, W10 Pro 1903

johnebaker wrote on 6/16/2016, 2:04 PM

Hi John CB

. . . . I am still lost on most of this despite a lot of reading. . . How do you ensure that the neutral colours are correctly balanced for RGB? . . . .

In a nutshell, neutral colours ie blacks, though greys to white have equal amounts of RGB, balance these correctly and all the other colours are automatically correct.  However there is a 'prescribed' method for doing this.

I am currently in Germany  - I will put up a full tutorial of how to do this when I am back home.

Cheers

John EB

 

Last changed by johnebaker on 6/16/2016, 2:04 PM, changed a total of 1 times.

Lateral thinking can get things done!

VPX, MEP Premium, MEP 2016, and earlier versions, Music Maker Premium, Music Maker 2016, 2015.

Running Windows 10 64bit on Intel i7-8700K 3.2 GHz, 16Gb RAM, 1Tb + 2 x 2Tb internal HDD + 60Gb internal SSD, + 6 x 2Tb ext HDDs, Sony FDR-AX53 Video camera, Contour HD 1080 and Sony HDR-AS30V Sports cams.

browj2 wrote on 6/17/2016, 7:22 AM

Hi John EB,

Thanks for your reply. Awaiting the prescribed method/tutorial.

In the meantime, have a good, safe trip. Make sure that you get home before Br Exits the EU.

Last changed by browj2 on 6/17/2016, 7:22 AM, changed a total of 1 times.

John C.B.

Desktop System - Windows 10 Home 1903; 16Gb RAM; i7 CPU 860@2.80Gz; ATI Radeon HD5770 w1GB; SSD 500GB, HD 2TB; others 1.5TB, 3TB, 500GB, 4TB, 5TB, 6TB; dual monitors - 27" main, 25" secondary; Casio WK-225 piano keyboard; M-Audio M-Track USB mixer; Notebook - Microsoft Surface Pro 4, i5, 8 GB RAM, 256 SSD, W10 Pro 1903