Photon Focus MV-D1024E-3D01-160, User Manual

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4 Functionality
The 3D data block contains the following information:
• Peak coordinate (2 bytes). The 1st and the 2nd byte (PEAK [15:0]) indicate the calculated
peak position of the laser line within the 2D raw image. PEAK [15:6] is the integer part of
the peak coordinate and PEAK [5:0] is the fractional part.
• Laser line width (1 byte). The 3rd byte (WIDTH [7:0]) contains the width of the laser line
(see Fig. 4.36). WIDTH [7:2] is the integer part and WIDTH [1:0] is the fractional part.
• Detection quality indicator (1 word). The 4th byte (QUAL [(gr-1):0]) contains the maximum
height of the laser line (see Fig. 4.36). For the bit assignment of the quality indicator in 8
bit, 10 bit or 12 bit greyscale resolution see Table 4.6. In this context the abbreviation "gr"
is used for the greyscale resolution (8 bit, 10 bit or 12 bit).
• Reserved (4 byte).
Greyscale Resolution Quality Indicator
8 bit QUAL[7:0]
10 bit QUAL[9:0]
12 bit QUAL[11:0]
Table 4.6: Bit assignment of the quality indicator depends on the greyscale resolution
The 3D data block is always given in 8 bit format, independent of the choosen
greyscale resolution, except QUAL. The 8 bit data is located on the LSBs of the
pixel and the remaining bits are set to 0.
4.8.4 Interpolation Technique
Structured light based systems crucially rely on an accurate determination of the peak position
of the Gaussian shaped laser line. The Peak Detector algorithm in the MV-D1024E-3D01-160
camera applies nonlinear interpolation techniques, where up to 64 data points can be inserted
between two pixels within the Gaussian shaped laser line. This technique is superior to other
commonly used detection techniques, such as the detection of peak pixel intensity across the
laser line (resulting in pixel accuracy) or the thresholding of the Gaussian and calculation of the
average (resulting in subpixel accuracy).
The Peak Detector analyzes all image data that are enclosed within the selected
region of interest (ROI).
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