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S12U / S14UC - Good (and fast) image correction plugin?

Last post 10-09-2011, 7:34 by culpanr. 3 replies.
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  •  10-08-2011, 14:36 494600

    S12U / S14UC - Good (and fast) image correction plugin?

    Tryiing to improve footage shot in a sports hall that had somewhat "dim & dingy" lighting - footage has turned out a little underexposed and lacking in "vibrance" (for want of a better term)

    So, I would like to adjust:

    i. Brightness and/or contrast - to restore full dynamic range (0, 0, 0) to (255, 255, 255)
    ii. Small positive gamma cvorrection to lighten the darker parts (e.g. the murky corners of the hall)
    iii. Small increase in colour saturation to counteract adjustments i. and ii.

    I have tried Studio's built-in "Studio Ultimate RTFX  Color Correctoon" - it is fast, but I have found it to be flawed:

    i. Altering the Gamma causes a shift of black level, that cannot be removed using brightness/contrast or gain/black level sliders.
    ii. Increasing both Gamma and Saturation can cause colour "mis-registration"; certain colours become spread beyond the edges of whatever object, somewhat like analogue "colour bleed" and they acquire a vertical stripey / flickery ettect.

    As an alternative to Studio's flawed "Color Correction" effect I have tried:

    i. JPsEffects | Color Adjust (0.1) - can achieve near-perfect results, but effect rendering is extremely slow (~ 1 frame/sec for AVCHD 1080i source)
    ii. WLFilter | Color Control (2.1) - fast, has good Gamma correction, but appears to use integer arithmetic and suffers from unexpected clipping of blacks or whites due to "overflow" of intermediate calculations when multiple adjustments are applied. Also, does not provide ability to increase colour saturation.

    Are there any other similar image correction plugins available (preferably free Wink ). In the meantime I will stick with JPsEffects and just have to put up with the fact that my video is going to take over a day to renderSad


  •  10-08-2011, 15:47 494608 in reply to 494600

    Re: S12U / S14UC - Good (and fast) image correction plugin?

    Hi Richard, in such conditions I use the Studio Ultimate RTFx / Lighting and increase the Video Gain.
  •  10-09-2011, 5:59 494661 in reply to 494608

    Re: S12U / S14UC - Good (and fast) image correction plugin?

    David Hunt:
    Hi Richard, in such conditions I use the Studio Ultimate RTFx / Lighting and increase the Video Gain.

    Did a quick test - increasing video gain alone causes too much clipping of whites; for my footage it needs to be tamed by reducing to around 2.2 and playing with the other controls too. But the controls are very unintuitive, both in their names and in what effect they appear to have on the image - and the documentation (in Studio 14 online help and the PDF manual) is an absolute joke!

    Rendering is faster than JPsEffects though - so maybe worth persevering to find a "nice" setting...


  •  10-09-2011, 7:34 494664 in reply to 494608

    Re: S12U / S14UC - Good (and fast) image correction plugin?

    Results of further experimentation with the "Lighting" effect

    (a) "Foreground Fill" and "Back Lighting" controls appear to be working by adding/removing an offset to darker or lighter areas of the image, making it hard to lighten the image and still retain a full dynamic range.
    (b) I still haven't sussed out the precise effect of the "Video Gain" slider:
    i. At a setting of 0.0 (all the way to the left) it has zero effect (as if "bypassed").
    ii. At low settings the image is black/very dark
    iii. At a setting of around 2.2/2.3, peak whites become as bright as in the original, yet overall the image still appears much darker
    iv. At a setting of around 2.5/2.6 the image appears overall as light as the original, but whites are severely clipped.
    (c) Only the "Brightness" control seems to be behaving intuitively!

    I got the best results from:
    (a) JPsEffects "Color Adjust" filter on its own - can do brightness, contrast, gamma and saturation adjustment all in one and get really good results.
    (b) Combination of WLFilter "Color Control" and Studio's own Color Correction; use WLFilter to do the brightness/contrast/gamma and use Studio's Color Correction filter to do the saturation. Not quite as good as JPsEffects (seems to have lost a little colour "vibrance" (turning up the saturation further doesn't make it look better, it just becomes garish)). But about 20x faster to render than JPsEffects - and can be previewed in real time without BG rendering. Smile

    So for "Quality" - I will need to use JPsEffects "Color Adjust", and for "Speed" use WLFilter "Color Cintrol" + Studio "Color Correction"


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