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FG Camera Library
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FG Camera Library
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The following WVGA sensor models are available for the VisionCam XM and the VisionSensor PV/PV2:
| Sensor | Type | Hardware | eFG_CAMERA_TYPE | Number of pixels | Pixel size | Optical format |
|---|---|---|---|---|---|---|
| MT9V032M | Monochrome | VisionCam XM | FG_CAMERA_TYPE_752_480_IMAGO_VCx_MT9V032M | 752 x 480 | 6 µm x 6 µm | 1/3" |
| VisionSensor PV | FG_CAMERA_TYPE_736_480_IMAGO_VSx_MT9V032M | 736 x 480 | ||||
| MT9V032C | Color | VisionCam XM | FG_CAMERA_TYPE_752_480_IMAGO_VCx_MT9V032C | 752 x 480 | ||
| VisionSensor PV | FG_CAMERA_TYPE_736_480_IMAGO_VSx_MT9V032C | 736 x 480 |
The supported pixel formats and maximum frame rates are listed below:
| Sensor | eFG_PIXEL_TYPE | Output format |
|---|---|---|
| MT9V032M (Monochrome) | FG_PIXEL_TYPE_Y_8 | 1 byte per pixel |
| FG_PIXEL_TYPE_Y_16 | 2 bytes per pixel containing 10 valid bits | |
| MT9V032C (Color) | FG_PIXEL_TYPE_Y_8 | Raw bayer, 1 byte per pixel |
| FG_PIXEL_TYPE_Y_16 | Raw bayer, 2 bytes per pixel containing 10 valid bits | |
| FG_PIXEL_TYPE_RGB_24 | Hardware Demosaicing: 3 bytes per pixel containing 8 bit R/G/B | |
| FG_PIXEL_TYPE_RGBX_32 | Hardware Demosaicing: 4 bytes per pixel containing 8 bit R/G/B/dummy |
The frame rate can be increased be reducing the AOI size. Some examples are listed in the following table:
| AOI size | Max. frame rate |
|---|---|
| 752 x 480 | 63 |
| 640 x 480 | 72 |
| 752 x 240 | 116 |
| 320 x 240 | 138 |
The sensor supports the following special features:
| Property name | Description | FGCamera.so |
|---|---|---|
| Companding | Sets companding mode 0: disable companding → linear ADC conversion (default) 1: enable companding → higher resolustion at low light, lower resolution at high light | ≥ 1.1.2.0 |
| DigitalTestPattern | Enables test pattern using a constant pixel value: 0 .. 0x3FF → constant pixel value ≥ 0x400 → disable test pattern | ≥ 1.0.0.0 |
| ExposureMode | Configures the behavior of FG_set_shutter_time() for compensation of noise artifacts and for using shorter exposure times, see also Using short exposure times. This feature is only available for the VisionSensor PV and requires PRU firmware ≥ 1.1.0.0. 0: Integration time of the sensor equals specified shutter time 1: Integration time of the sensor is increased by 50 µs, the effective exposure time is controlled by the LED / strobe signal (default) | ≥ 1.2.0.0 |
| Mirror | Flips the image horizontally and / or vertically 0: no flipping (default) 1: flip horizontally 2: flip vertically 3: flip horizontally and vertically (rotation by 180°) Please note that the order of color components for raw Bayer format doesn't depend on this setting. | ≥ 1.2.8.0 |
The hardware demosaicing feature of the VisionCam XM is automatically enabled by using the pixel type FG_PIXEL_TYPE_RGB_24 or FG_PIXEL_TYPE_RGBX_32 with FG_set_aoi().
The demosaicing algorithm uses a high quality 5x5 filter, see High-Quality Linear Interpolation for Demosaicing of Bayer-Patterned Color Images for a description.
The function FG_set_gain_rgb() can be used to adjust the gain for each color component.
The sensor supports a minimum integration time of 110 µs. The sensor also accumulates more noise at the end of the integration time. This mainly becomes noticeable at short exposure times (e.g. < 150 µs).
To work around both problems, the effective exposure time can be controlled by adjusting the LED strobe timing. The strobe timing can be adjusted down to 1 µs. Using a longer sensor integration time than the selected strobe time helps to avoid light hitting the sensor at the noise sensitive end of the integration period.
1.14.0