Feature Request: Advanced Colour Correction

[quamt]

@rigaya,

Could you add an advanced colour correction feature?
While the current --vpp-tweak and --vpp-curves commands are helpful, they do not offer the same precision and control as advanced colour correction.

The current --vpp-tweak command allows basic adjustments to brightness, contrast, gamma, saturation, and hue.
However, it cannot independently adjust offsets and gains for individual RGB channels.
Although powerful, the --vpp-curves command can be complex and less intuitive for many users who prefer straightforward adjustments for colour correction.

An advanced colour correction feature would provide the following benefits:

1. Precision: Independent control over RGB channel offsets and gains for more precise colour adjustments.
2. Independent Channel Control: Ability to correct specific colour imbalances without affecting the entire image.
3. Enhanced Flexibility: Detailed and fine-tuned colour corrections can be achieved, offering greater flexibility in achieving desired visual effects.
4. Incremental Adjustments: Control in increments of 1 with a range of +/-256 allows for very fine-grained adjustments, which is crucial for achieving professional-grade results.

For reference, here are the parameters from AviUtl's advanced colour correction panel, which demonstrates the level of control that would greatly benefit QSVEnc users:

- Y(offs)
- Y(gain)
- Cb(offs)
- Cb(gain)
- Cr(offs)
- Cr(gain)
- R(offs)
- R(gain)
- R(gamm)
- G(offs)
- G(gain)
- G(gamm)
- B(offs)
- B(gain)
- B(gamm)

These adjustments are made in increments of 1 and have a range of +/-256, which allows for precise and detailed colour correction. Implementing similar parameters in QSVEnc could significantly enhance its utility for users requiring detailed colour correction capabilities.

I understand you are extremely busy, and you do not need to worry about implementing this feature. Please take the necessary time to consider this request. I understand if integrating this feature is not feasible due to technical limitations or other constraints. I truly appreciate all the hard work you put into developing and maintaining QSVEnc.

Thank you,
quamt

[rigaya]

QSVEnc 7.68 adds support for per channel color tweak to --vpp-tweak.

Please note that the parameter range is not +/-256 but using float, to be consistent with previous vpp-tweak parameters.

[quamt]

I appreciate you implementing the per-channel color tweak.
I will test it in the next few days and report back.
Thank you very much.

[quamt]

It looks all good so far.
I will close this.
If I should encounter any issues, I will open a new one.
Thank you again for your hard work.