Point Grey Flea3 FL3-U3 - 5.2 Pixel Formats

Point Grey Flea3 USB 3.0 Technical Reference 5 Video Formats, Modes and Frame Rates
On FL3-U3-32S2 models, the ROI size can range from 16 to 2080 pixels wide and 2 to 1080 pixels high, making the
minimum image size 16 x 2 and the maximum size 2080 x 1080. The ROI can change position within the entire
2080x1552 pixel array.
Specifying an image size outside the allowable parameters of the Mode 8 cut-out returns an error
from register VALUE_SETTING: 07Ch (page 148).
The first two frames following a change in the size or position of the Mode 8 cut-out are invalid.
Mode 10 (FL3-U3-88S2)
For FL3-U3-88S2, mode 10 allows a maximum image size of 4000 x 3000 (12 MP) with a maximum frame rate of
15FPS. There is no pixel correction (page 127) in mode 10. Only 8-bit and 12-bit pixel formats support 12 MP; 16-bit
pixel formats support 11 MP and 24-bit pixel formats support 7.4 MP.
5.1.2 Calculating Format 7 Frame Rates
The theoretical frame rate (FPS) that can be achieved given the number of packets per frame (PPF) can be calculated
as follows:
FPS = 1 / (Packets per Frame * 125us)
An estimate for the number of packets per frame can be determined according to the following:
PPF = (Image_Size * Bytes_Per_Pixel) / Bytes_Per_Packet
For the exact number of packets per frame, query the PACKET_PER_FRAME_INQ register. For the number of bytes
per packet, query the BYTE_PER_PACKET register.
For example, assuming an image size of 1032x776, pixel format of Mono16 (2 bytes per pixel), and 3880 bytes per
packet, the calculation would be as follows:
FPS = 1 / ((1032*776*2 / 3880 ) * 0.000125 )
FPS = 1 / (412.8 * 0.000125 )
FPS = 19.38
5.2 Pixel Formats
Pixel formats are an encoding scheme by which color or monochrome images are produced from raw image data.
Most pixel formats are numbered 8, 12, or 16 to represent the number of bits per pixel.
The camera's ADC (page 12), which digitizes the images , is configured to a fixed bit output. If the pixel format selected
has fewer bits per pixel than the ADCoutput, the least significant bits are dropped. If the pixel format selected has
greater bits per pixel than the ADC output, the least significant bits are padded with zeros.
Revised 9/27/2012
Copyright ©2011-2012 Point Grey Research Inc.
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