Caption data coding/decoding systems and methods that includes key data indicating intermediate levels of attenuation in the vicinity of the caption

A video image control method for superimposing a caption on a video image for display, comprising:

• receiving coded key data representing one of a maximum attenuation rate, a minimum attenuation rate, and one or more intermediate attenuation rates between the maximum attenuation rate and the minimum attenuation rate, of the video image in a vicinity of the caption;
• decoding the coded key data;
• and
• attenuating the video image in the vicinity of the caption at a rate indicated by the decoded key data.

A video image control method for superimposing a caption on a video image for display, comprising:

• receiving coded key data representing an attenuation rate of the video image in a vicinity of the caption;
• decoding the coded key data;
• attenuating the video image in the vicinity of the caption at a rate indicated by the decoded key data;
• making the attenuation rate of said video image minimum when said decoded key data is minimum data;
• making the attenuation rate of said video image maximum when said key data is maximum data;
• and
• making the attenuation rate of said video image correspond to the magnitude of said value when said key data is a value between the minimum and the maximum.

A caption coding system for coding a caption to be superimposed on a video image for display, comprising:

• caption data coding means for coding caption data representing a caption to be superimposed on a video image for display,
• key data coding means for coding key data representing one of a maximum attenuation rate, a minimum attenuation rate, and one or more intermediate attenuation rates between the maximum attenuation rate and the minimum attenuation rate, of the video image in a vicinity of the caption;
• and
• combining means for combining the coded caption data and the coded key data with video image data that represents the video image, to generate a combined image signal.

A video image control system for superimposing a caption on a video image for display, comprising:

• means for receiving a coded key data representing one of a maximum attenuation rate, a minimum attenuation rate, and one or more intermediate attenuation rates between the maximum attenuation rate and the minimum attenuation rate, of the video image in a vicinity of the caption when the caption is superimposed on the video image;
• decoding means for decoding the coded key data;
• and
• attenuating means for attenuating the video image based on the decoded key data.

A video image control system for superimposing a caption on a video image for display, comprising:

• means for receiving a coded key data representing an attenuation rate of the video image in a vicinity of the caption when the caption is superimposed on the video image;
• decoding means for decoding the coded key data;
• and
• attenuating means for attenuating the video image based on the decoded key data
• wherein the attenuating means makes the attenuation rate of said video image minimum when the decoded key data is minimum data, makes the attenuation rate of the video image maximum when the key data is maximum data and, makes the attenuation rate of the video image correspond to the magnitude of the value, when the key data is a value between the minimum and the maximum.

A recording medium having a video image signal recorded thereon for controlling a display apparatus to display the video image signal, the recording medium being created by:

• coding a video image;
• coding caption data representing a caption to be superimposed on the video image for display;
• coding key data representing one of a maximum attenuation rate, a minimum attenuation rate, and one or more intermediate attenuation rates between the maximum attenuation rate and the minimum attenuation rate, of the video image in a vicinity of the caption when the caption is superimposed on the video image by the display apparatus;
• and
• recording the coded video image, caption data, and key data onto the recording medium.

A caption coding method for coding a caption, represented by caption data, to be superimposed on a video image for display, comprising:

• coding the caption data representing the caption to be superimposed on the video image for display;
• coding key data to have a value corresponding to an attenuation rate of portions of the video image in a vicinity of the caption;
• combining the caption data and the key data with video image data that represents the video image, to generate a combined image signal
• wherein, in the caption data coding step and the key data coding step, each of the caption data and the key data are expressed by a predetermined number of bits and one of the caption data and the key data, but not both, is selectively coded into a predetermined portion of the combined image signal.

A caption coding method for coding a caption, represented by caption data, to be superimposed on a video image for display, comprising:

• coding the caption data representing the caption to be superimposed on the video image for display, including combining color difference data of the caption with an offset value corresponding to the coordinate position, of the video image, of a change point of the color difference data, to determine a chroma vector, and coding the chroma vector into the caption data;
• coding key data to have a value corresponding to an attenuation rate of portions of the video image in a vicinity of the caption;
• and
• combining the caption data and the key data with video image data that represents the video image, to generate a combined image signal.

A caption coding system for coding a caption to be superimposed on a video image for display, comprising:

• caption data coding means for coding caption data representing a caption to be superimposed on a video image for display,
• key data coding means for coding key data representing an attenuation rate of portions of the video image in a vicinity of the caption;
• and
• combining means for combining the coded caption data and the coded key data with video image data that represents the video image, to generate a combined image signal,
• wherein the caption data coding means and the key data coding means selectively expresses each of the caption data and the key data by a predetermined number of bits and codes one of the caption data and the key data, but not both, into a predetermined portion of the combined image signal.

A caption coding system for coding a caption to be superimposed on a video image for display, comprising:

• caption data coding means for coding caption data representing a caption to be superimposed on a video image for display,
• key data coding means for coding key data representing an attenuation rate of portions of the video image in a vicinity of the caption;
• and
• combining means for combining the coded caption data and the coded key data with video image data that represents the video image, to generate a combined image signal,
• wherein the caption data coding means codes brightness data of the caption as the caption data, and the coding means includes combining means for combining color difference data of the caption with the coded brightness data of the caption as a chroma vector corresponding to a predetermined offset value and a coordinate position, of the video image, of a change point of the color difference data of the caption.