Commands

The filter supports the following commands:

'contrast'

Set the contrast expression.

'brightness'

Set the brightness expression.

'saturation'

Set the saturation expression.

'gamma'

Set the gamma expression.

'gamma_r'

Set the gamma_r expression.

'gamma_g'

Set gamma_g expression.

'gamma_b'

Set gamma_b expression.

'gamma_weight'

Set gamma_weight expression.

The command accepts the same syntax of the corresponding option.

If the specified expression is not valid, it is kept at its current value.