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5 Functionality
5.9
Grey Level Transformation (LUT)
Grey level transformation is remapping of the grey level values of an input image to new
values. The look-up table (LUT) is used to convert the greyscale value of each pixel in an image
into another grey value. It is typically used to implement a transfer curve for contrast
expansion. The camera performs a 12-to-8-bit mapping, so that 4096 input grey levels can be
mapped to 256 output grey levels. The use of the three available modes is explained in the next
sections. Two LUT and a Region-LUT feature are available in the camera (see Section 5.9.4).
The LUT is implemented as a 12-to-8 bit LUT to be compatible with other Pho-
tonfocus cameras. Bits 0 & 1 of the 12 bit LUT input data are set to random
values.
The output grey level resolution of the look-up table (independent of gain,
gamma or user-definded mode) is always 8 bit.
There are 2 predefined functions, which generate a look-up table and transfer it
to the camera. For other transfer functions the user can define his own LUT file.
Some commonly used transfer curves are shown in Fig. 5.28. Line a denotes a negative or
inverse transformation, line b enhances the image contrast between grey values x0 and x1.
Line c shows brightness thresholding and the result is an image with only black and white grey
levels. and line d applies a gamma correction (see also Section 5.9.2).
a
y = f ( x )
x
x
m a x
x
0
x
1
y
m a x
b
c
d
Figure 5.28: Commonly used LUT transfer curves
5.9.1
Gain
The ’Gain’ mode performs a digital, linear amplification with clamping (see Fig. 5.29). It is
configurable in the range from 1.0 to 4.0 (e.g. 1.234).
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MAN069 12/2018 V1.1
Summary of Contents for MV1-D4096 Series
Page 1: ...Photonfocus MV1 D4096 Camera Series CMOS camera with GigE interface MAN069 12 2018 V1 1 ...
Page 10: ...1 Preface 10 of 123 MAN069 12 2018 V1 1 ...
Page 12: ...2 Introduction 12 of 123 MAN069 12 2018 V1 1 ...
Page 32: ...4 Product Specification 32 of 123 MAN069 12 2018 V1 1 ...
Page 94: ...6 Hardware Interface 94 of 123 MAN069 12 2018 V1 1 ...
Page 108: ...7 Software 108 of 123 MAN069 12 2018 V1 1 ...
Page 110: ...8 Mechanical Considerations 110 of 123 MAN069 12 2018 V1 1 ...
Page 112: ...9 Troubleshooting 112 of 123 MAN069 12 2018 V1 1 ...
Page 118: ...12 Support and Repair 118 of 123 MAN069 12 2018 V1 1 ...
Page 120: ...13 References 120 of 123 MAN069 12 2018 V1 1 ...
Page 124: ...B Camera Revisions 124 of 123 MAN069 12 2018 V1 1 ...