Image-processing apparatus and method

An image-processing method comprising:

• inversely quantizing, using an inverse quantization unit, first quantized data using a first quantization table, thereby generating frequency image data;
• quantizing, using a quantization unit, the frequency image data using a second quantization table different from the first quantization table, thereby generating second quantized data;
• and
• embedding, using an information-embedding unit, additional information into the second quantized data,
• wherein each of the first and second quantization tables comprises elements at which the additional information is to be embedded, and wherein the elements in the second quantization table are smaller in value than the elements in the first quantization table.

A computer readable storage medium having an image-processing program recorded therein in a computer readable manner, said image-processing program causing a computer to execute a method comprising:

• inversely quantizing, using an inverse quantization unit, first quantized data using a first quantization table, thereby generating frequency image data;
• quantizing, using a Quantization unit, the frequency image data using a second quantization table different from the first quantization table, thereby generating second quantized data;
• and
• embedding, using an information-embedding unit, additional information into the second quantized data,
• wherein each of the first and second quantization tables comprises elements at which the additional information is to be embedded, and wherein the elements in the second quantization table are smaller in value than the elements in the first quantization table.