JEITA CP-3451
- 69 -
The method of describing the various image width data with and without padding is given in Figure 30. It shall be
noted carefully that the value of SOF is used in some cases to describe the valid image width, and in others to
describe the image width after padding.
Figure 30 Image Data Width Description
Table 19 gives examples of information recorded in the direction of image width and padding data width, for each of
cases A, B, and C of Figure 30.
Table 19 Typical Width Direction Information and Padding Data
Valid Image Width
PixelXDimension
SOF Information
Compressed Data
Padding Width
A
640
640
640
640
0
B
634
634
634
640
6 (< 1MCU)
C
620
620
640
640
20 (> 1MCU)
Padding in
multiple of 64 ?
PixelXDimension = X
SOF.X = X
Padding in
multiple of 64
Xpad = Padding width
Xpad larger than 16 ?
PixelXDimension = X
SOF.X = X
PixelXDimension = X
SOF.X = X + Xpad
JPEG Compression
No
Yes
No
X:
Valid image width
SOF.X :
Holizontal line value in SOF
PixelXDimension : PixelXDimension tag value
X=multiple of 64 ?
X=multiple of 16 ?
Padding in
multiple of 16
No
Yes
Yes
No
Yes
A
B
C