Digital signal encoding and decoding device and method

A digital data decoding device, comprising:

• a compressed encoded image data input unit that inputs compressed encoded image data of s-bit lengths, the s being a natural number, which has an initial pixel value data part in which first pixel value data of a first pixel which senses a first color are recorded as they are as first initial pixel value data and a compressed encoded pixel value data part in which first compressed encoded pixel value data indicating second pixel value data of a second pixel which senses the first color being positioned in the vicinity of the first pixel are recorded;
• an offset value setting unit that obtains a difference between the first initial pixel value data and a first quantization reference value being set as a first offset value;
• an inverse quantization unit that inversely quantizes the first compressed encoded pixel value data by using a first quantization width being set to obtain first inversely quantized pixel value data;
• and
• a decoded pixel value generation unit that obtains a sum of the first inversely quantized pixel value data and the first offset value to generate first decoded pixel value data.

A digital data encoding method, for receiving pixel value data in a digital format indicating a signal from a light receiving unit in which a pixel for sensing a first color and a pixel for sensing a second color are periodically arranged and processing the pixel value data, comprising:

• generating and outputting a difference value between first pixel value data of a first pixel which senses a first color and second pixel value data of a second pixel which senses the first color and is positioned in the vicinity of the first pixel as a first pixel difference value and generating and outputting a difference value between third pixel value data of a third pixel which senses a second color and fourth pixel value data of a fourth pixel which senses a second color and is positioned in the vicinity of the third pixel as a second pixel difference value;
• obtaining a maximum value between an absolute value of the first pixel difference value and an absolute value of the second pixel difference value as a maximum pixel value difference, determining a value being greater than or equal to the maximum pixel value difference, and determining the value as a quantization reference value;
• setting a difference between the first pixel value data and the quantization reference value as a first offset value and setting a difference between the third pixel value data and the quantization reference value as a second offset value;
• setting a difference between the second pixel value data and the first offset value as a first value to be quantized and setting a difference between the fourth pixel value data and the second offset value as a second value to be quantized;
• and
• quantizing the first value to be quantized and the second value to be quantized to obtain first compressed encoded pixel value data and second compressed encoded pixel value data, respectively.

A digital data decoding method, comprising:

• inputting compressed encoded image data of s-bit lengths, the s being a natural number, which has an initial pixel value data part in which first pixel value data of a first pixel which senses a first color are recorded as they are as first initial pixel value data and a compressed encoded pixel value data part in which first compressed encoded pixel value data indicating second pixel value data of a second pixel which senses the first color being positioned in the vicinity of the first pixel are recorded;
• obtaining a difference between the first initial pixel value data and first quantization reference value being set as a first offset value;
• inversely quantizing the first compressed encoded pixel value data by using first quantization width being set to obtain first inversely quantized pixel value data;
• and
• obtaining a sum of the first inversely quantized pixel value data and the first offset value to generate first decoded pixel value data.