Non-additive video mixer

A non-additive mixer for video signals, comprising:

• summation means coupled to receive a first video input and a second video input and producing an output signal dependent on the difference between the first and second video inputs;
• a chrominance (blocking) filter for receiving the output signal and producing a filtered output signal;
• a multiplier coupled to receive the filtered output signal and multiply it by a gain control signal to produce a mixer control signal that is a linear function of the difference between a luminance component of the first video input and a luminance component of the second video inputs;
• and
• a mixer coupled to receive the first video input and the second video input and producing a video output representative of the product of the first video input and the mixer control signal plus the product of the second video input and the complement of the mixer control signal.

A method for non-additively mixing video signals, the method comprising the steps of:

• chrominance (blocking) filtering a first video input to produce a first luminance signal;
• chrominance (blocking) filtering a second video input to produce a second luminance signal;
• forming a mixer control signal that is a linear function of the difference between the first luminance signal and the second luminance signal;
• and
• combining the first video input and the second video input to produce a video output representative of the product of the first video input and the mixer control signal plus the product of the second video input and the complement of the mixer control signal.

A method for non-additively mixing video signals, the method comprising the steps of:

• forming a summation output signal dependent upon the difference between a first video input and a second video input;
• chrominance (blocking) filtering the summation output signal to produce a filtered output signal;
• multiplying the filtered output signal by a gain control signal to produce a mixer control signal that is a linear function of the difference between a luminance component of the first video input and a luminance component of the second video input;
• and
• combining the first video input and the second video input to produce a video output representative of the product of the first video input and the mixer control signal plus the product of the second video input and the complement of the mixer control signal.

A non-additive mixer for component video signals each having a luminance component and chrominance A and chrominance B components associated therewith, said non-additive mixer comprising:

• summation means for producing a mixer control signal that is a linear function of the difference between a first luminance input component and a second luminance input component;
• a luminance mixer coupled to receive the first and second luminance input components and producing a luminance output component representative of the product of the first luminance input component and the mixer control signal plus the product of the second luminance input component and the complement of the mixer control signal;
• a first chrominance mixer coupled to receive the chrominance A components associated with the first and second luminance input components respectively and producing a chrominance A output component representative of the product of the chrominance A component associated with the first luminance input component and the mixer control signal plus the product of the chrominance A component associated with the second luminance input component and the complement of said mixer control signal;
• and
• a second chrominance mixer coupled to receive the chrominance B components associated with the first and second luminance input components respectively and producing a chrominance B output component representative of the product of the chrominance B component associated with the first luminance input component and the mixer control signal plus the product of the chrominance B component associated with the second luminance input component and the complement of said mixer control signal.

A method for non-additively mixing component video signals each having a luminance component and chrominance A and chrominance B components, the method comprising the steps of:

• forming a mixer control signal that is a linear function of the difference between a first luminance input component and a second luminance input component;
• combining the first and second luminance input components to produce a luminance output component representative of the product of the first luminance input component and the mixer control signal plus the product of the second luminance input component and the complement of the mixer control signal;
• combining the chrominance A components associated with the first and second luminance input components respectively to produce a chrominance A output component representative of the product of the chrominance A component associated with the first luminance input component and the mixer control signal plus the product of the chrominance A component associated with the second luminance input component and the complement of the mixer control signal;
• and
• combining the chrominance B components associated with the first and second luminance input components respectively to produce a chrominance B output component representative of the product of the chrominance B component associated with the first luminance input component and the mixer control signal plus the product of the chrominance B component associated with the second luminance input component and the complement of the mixer control signal.