JEITA CP-3451
- 126 -
F.1
Converting Image Data
Flashpix compressed image data consists of JPEG-compressed 64 x 64-pixel tiles. Converting JPEG images
without restart markers to Flashpix images requires that the JPEG data be expanded and re-compressed, which
can lead to image quality loss. By inserting restart markers at 64-pixel Interoperability, Flashpix images of the
maximum resolution can be generated simply by rearranging the JPEG-compressed data.
Figure 54 shows how compressed data is rearranged using restart markers.
Figure 54 Conversion to Flashpix Using Restart Markers
Y DCT Block (8x8)
CrCb DCT Block (8x8)
Y,Cb,Cr pixel
Y pixel
(a) MCU (4:2:2)
(0,0)
(0,1)
(0,2)
(0,3)
(0,4)
(0,5)
(0,6)
(0,7)
(0,8)
(0,0)
(0,1)
(0,2)
(0,3)
(1,0)
(1,1)
(1,2)
(1,3)
(2,0)
(c) Recording order
FPXR(JPEG)
FlashPix
Restart Marker
MCU
(4:2:2)
(0,0)
(0,1)
(0,2)
(0,3)
(0,4)
(1,0)
(1,1)
(1,2)
(1,3)
(1,4)
(2,0)
(2,1)
(2,2)
(2,3)
(2,4)
(3,0)
(3,1)
(3,2)
(3,3)
(3,4)
(4,0)
(4,1)
(4,2)
(4,3)
(4,4)
(5,0)
(5,1)
(5,2)
(5,3)
(5,4)
(6,0)
(6,1)
(6,2)
(6,3)
(6,4)
(7,0)
(7,1)
(7,2)
(7,3)
(7,4)
(8,0)
(8,1)
(8,2)
(8,3)
(8,4)
(x,y)
1 Tile block (64x64)
(b) Tile block
Restart Marker
