Memory apparatus for digital picture signal, writing method thereof, and reading method thereof

A writing method for writing data of which a digital picture signal has been processed on the real time basis to memory means disposed on a common semiconductor substrate, the method comprising the step of:

• performing a hierarchical encoding process for generating at least data in a first hierarchical level and data in a second hierarchical level with the input picture data, the data in the first hierarchical level being different from the data in the second hierarchical level in resolutions,
• the hierarchical encoding step comprising the steps of:
• forming the data in the second hierarchical level with the average value of every N pixels of the data in the first hierarchical level;
• and
• outputting (N−1) pixels of the data in the first hierarchial level and one pixel of the data in the second hierarchical level to said memory means.

A writing method for writing data of which a digital picture signal has been processed on the real time basis to memory means disposed on a common semiconductor substrate, the writing method comprising the step of:

• performing a hierarchical encoding process for generating at least data in a first hierarchical level and data in a second hierarchical level with the input picture data, the data in the first hierarchical level being different from the data in the second hierarchical level in resolutions,
• the hierarchical encoding step comprising the steps of:
• forming the data in the second hierarchical level with the average value of every N pixels of the data in the first hierarchical level;
• generating (N−1) difference values between the average value of the data in the second hierarchical level and the data in the first hierarchical level;
• and
• outputting the (N−1) difference values of the data in the first hierarchical level and the data in the second hierarchical level to said memory means.

A reading method for causing signal processing means to read data of which a digital picture signal has been processed from memory means, the signal processing means and the memory means being disposed on a common semiconductor substrate, the reading method comprising the step of:

• performing a hierarchical decoding process, corresponding to a hierarchical encoding process, for generating at least data in a first hierarchical level and data in a second hierarchical level with the input picture data, the data in the first hierarchical level being different from the data in the second hierarchical level in resolutions,
• the hierarchical decoding process step comprising the steps of:
• restoring data in the first hierarchical level that has not been written to the memory means with the data in the first hierarchical level and the data in the second hierarchical level being read from the memory means;
• and
• selectively outputting the restored data in the first hierarchical level or the restored data in the second hierarchical level.