Image data sampling method

A method for sampling image data from an image frame with component video, the image frame including a first component frame, a second component frame and a third component frame, and the method comprising steps of:

• selecting a first component portion, a second component portion and a third component portion from the first component frame, the second component frame and the third component frame, respectively;
• operating said first component portion, said second component portion and said third component portion to result in a first component intermediate portion derived from said first component portion, a second component intermediate portion derived from said second component portion and a third component intermediate portion derived from said third component portion;
• and
• operating said first component intermediate portion, said second component intermediate portion and said third component intermediate portion to obtain a sampled unit.

A method for sampling image data from an image frame with component video, the image frame including a Y-component frame, a Cb-component frame and a Cr-component frame, and the method comprising steps of:

• selecting a Y-component portion, a Cb-component portion and a Cr-component portion from the Y-component frame, the Cb-component frame and the Cr-component frame, respectively;
• operating said Y-component portion, said Cb-component portion and said Cr-component portion according to a sub-sampling algorithm for JPEG or MPEG compression to result in a Y-component intermediate portion, a Cb-component intermediate portion and a Cr-component intermediate portion;
• and
• operating said Y-component intermediate portion, said Cb-component intermediate portion and said Cr-component intermediate portion to obtain a minimum coded unit of 2×2 block array for JPEG or MPEG compression, wherein said 2×2 block array includes two Y-component blocks selected from said Y-component intermediate portion, one Cb-component block selected from said Cb-component intermediate portion, and one Cr-component block selected from said Cr-component intermediate portion.