Datasheet

PDF: 09005aef8202ec2e/Source: 09005aef8202ebf7 Micron Technology, Inc., reserves the right to change products or specifications without notice.
MT9D111__7_REV5.fm - Rev. B 2/06 EN
159 ©2004 Micron Technology, Inc. All rights reserved.
MT9D111 - 1/3.2-Inch 2-Megapixel SOC Digital Image Sensor
Start-Up and Usage
Micron Confidential and Proprietary
Figure 40: Lens Correction Zones
Lens Correction Procedure
The goal of the lens shading correction is to achieve a constant sensitivity across the
entire image area after the correction is applied. In order to accomplish this, each
incoming pixel value is multiplied with a correction function F (x, y), which is dependent
on the location of the pixel. The corrected pixel data, P
OUT
, can be expressed in the fol-
lowing term:
(EQ 1)
Within each zone described above, the correction function can be expressed with a fol-
lowing equation, as follows:
(EQ 2)
where
(EQ 3)
are piecewise quadratic polynomial functions that are independent in each x and y
dimension
k and G are constants that can be used to increase lens correction at the image corners
(k) and to offset the LC magnitude for all zones and colors (G)
The expressions
(EQ 4)
X
0
X
1
X
2
Y
1
X
5
X
4
X
3
Y
0
Y
2
Y
5
Y
4
Y
3
Array
Center
C
Y
C
X
X
P
OUT
xy , ()= P
IN
xy , () * F xy , ()
F xy
, () = φ xx
2
, () ϕ yy
2
, () + k* φ xx
2
, ()* ϕ xx
2
, () * ϕ yy
2
, ()-G+
φ xx
2
, () and ϕ yy
2
, ()
φ xx
2
, () and ϕ yy
2
, ()