Specifications

Image processing

Goldeye Technical Manual V2.4.0

Short introduction: Two-point correction

(A, B, E, J, K, N)

The two-point correction is the most elaborate correction module of the

Goldeye xy-... camera models. For this reason initially a general survey of the

two-point correction functioning shall be given.

By means of the two-point correction (also called gain offset correction) usu-

ally, the distinctive underground structure of the InGaAs sensor can be equal-

ized. The target is to transmit the individual characteristic curve of each pixel to

a set characteristic curve, being valid for all pixels. In order to achieve this

result, the effective characteristic curve of each single pixel is determined by

taking up data samples. A linear characteristic curve is supposed so that two

data samples are sufficient for a definite determination. By means of recording

two reference images at the light levels T

and T

the data samples can be

determined for all pixels. Furthermore, the digital set values J and K each

belonging to the light levels T

and T

are determined.

Owing to the four parameters mentioned above, the two-point correction is now

able to modify the gain and the offset of each pixel characteristic curve in a way

that it is congruent with the set characteristic curve. Therefore, in an optimum

linear case, an image structure, caused by the sensor, does no longer occur. The

below mentioned diagram tries to exemplary explain the facts on the basis of

one single pixel characteristic curve:

Note



For more information see Chapter Basic parameters and com-

mands on page 59.

This will probably be sufficient for most users, due to the fact

that the determining and adjustment of nearly all parameters

is already executed ex factory and normally, no user interven-

tion is necessary at all.

For more extensive details of the current parameters see Chap-

ter Advanced parameters and commands on page 63.

Figure 21: Two-point correction