Chromakey effect apparatus

A chromakey effect apparatus comprising:

• means for receiving red, green and blue channel television signals containing a chromakey area and for producing a chromakey signal;
• means for generating an area signal to restrict a desired region on a television picture;
• gate means responsive to said area signal for passing the chromakey signal;
• color killing subcarrier generating means for generating a color killing subcarrier to cancel the color of the chromakey area;
• adder means for adding said color killing subcarrier to the television signal containing the chromakey area at the timing of the key signal fed from said gate means;
• and
• means for keying another television signal into the television signal fed from said adder means at the timing of the key signal supplied from said gate means.

A chromakey effect apparatus comprising:

• means for receiving red, green and blue channel television signals containing a chromakey area and for producing a chromakey signal;
• means for generating an area signal to restrict a desired region on a television picture;
• color killing subcarrier generating means for generating a color killing subcarrier to cancel the color of the chromakey area;
• first adder means for adding said color killing subcarrier to the television signal containing the chromakey area at the timing of the chromakey signal;
• second adder means for adding said area signal to said chromakey signal;
• and
• means for keying another television signal into the television signal fed from said first adder means at the timing of the key signal supplied from said second adder means.

A chromakey effect apparatus comprising:

• means for receiving television signals containing a chromakey area and for producing a chromakey signal;
• means for generating an area signal to restrict a desired region on a television picture;
• first and second gate means responsive to said area signal and operative alternatively for passing said chromakey signal;
• color killing subcarrier generating means for generating a color killing subcarrier to cancel the color of the chromakey area;
• color conversion subcarrier generating means for generating a color conversion subcarrier having a predetermined phase and an amplitude;
• adder means for adding the color killing subcarrier to the television signal containing the chromakey area at the timing of the output of said first gate means, and adding the color conversion subcarrier to said television signal at the timing of the output of said second gate means;
• and
• means for keying another television signal into the television signal fed from said adder means at the timing of the output of said first gate means.