Robobot camera
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== camera settings == | == camera settings == | ||
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| − | + | === Data formats === | |
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The used camera is a 'Jieli Technology' camera of type 'USB PHY 2.0' (packed by Sandberg). | The used camera is a 'Jieli Technology' camera of type 'USB PHY 2.0' (packed by Sandberg). | ||
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It also supports "raw" format as YUYV 4:2:2, but it seems like data loss occurs (fragmented images), so do not use this format. | It also supports "raw" format as YUYV 4:2:2, but it seems like data loss occurs (fragmented images), so do not use this format. | ||
| + | |||
| + | === Use from OpenCV (C++) === | ||
| + | |||
| + | void setup() | ||
| + | { | ||
| + | int deviceID = dev; // 0 = open default camera | ||
| + | int apiID = cv::CAP_V4L2; //cv::CAP_ANY; // 0 = autodetect default API | ||
| + | // open selected camera using selected API | ||
| + | cap.open(deviceID, apiID); | ||
| + | // check if we succeeded | ||
| + | camIsOpen = cap.isOpened(); | ||
| + | if (not camIsOpen) | ||
| + | { | ||
| + | cerr << "ERROR! Unable to open camera\n"; | ||
| + | } | ||
| + | else | ||
| + | { | ||
| + | uint32_t fourcc = cv::VideoWriter::fourcc('M','J','P','G'); | ||
| + | cap.set(cv::CAP_PROP_FOURCC, fourcc); | ||
| + | // possible resolutions in JPEG coding | ||
| + | // (rows x columns) 320x640, 720x1280 | ||
| + | cap.set(cv::CAP_PROP_FRAME_HEIGHT, 720); | ||
| + | cap.set(cv::CAP_PROP_FRAME_WIDTH, 1280); | ||
| + | cap.set(cv::CAP_PROP_FPS, 25); | ||
| + | // now the camera is ready for frame capture. | ||
| + | // debug print of accepted format: | ||
| + | union FourChar | ||
| + | { // the four characters are coded into a 32 bit integer. | ||
| + | uint32_t cc4; | ||
| + | char ccc[4]; | ||
| + | } fmt; | ||
| + | fmt.cc4 = cap.get(cv::CAP_PROP_FOURCC); // get format | ||
| + | printf("# Video device %d: width=%g, height=%g, format=%c%c%c%c, FPS=%g\n", | ||
| + | dev, | ||
| + | cap.get(cv::CAP_PROP_FRAME_WIDTH), | ||
| + | cap.get(cv::CAP_PROP_FRAME_HEIGHT), | ||
| + | fmt.ccc[0], fmt.ccc[1], fmt.ccc[2], fmt.ccc[3], | ||
| + | cap.get(cv::CAP_PROP_FPS)); | ||
| + | } | ||
Revision as of 12:13, 6 December 2022
Back to Robobot
camera settings
Data formats
The used camera is a 'Jieli Technology' camera of type 'USB PHY 2.0' (packed by Sandberg).
The camera has limited control capabilities but supports the following data formats.
- MJPG coded 640 x 320 pixels at 25 or 30 FPS
- MJPG coded 1280 x 720 pixels at 25 or 30 FPS
- MJPG coded 1920 x 1080 pixels at 25 or 30 FPS
- MJPG coded 640 x 480 pixels at 25 or 30 FPS, cuts parts of the image to fit the format
It also supports "raw" format as YUYV 4:2:2, but it seems like data loss occurs (fragmented images), so do not use this format.
Use from OpenCV (C++)
void setup() {
int deviceID = dev; // 0 = open default camera
int apiID = cv::CAP_V4L2; //cv::CAP_ANY; // 0 = autodetect default API
// open selected camera using selected API
cap.open(deviceID, apiID);
// check if we succeeded
camIsOpen = cap.isOpened();
if (not camIsOpen)
{
cerr << "ERROR! Unable to open camera\n";
}
else
{
uint32_t fourcc = cv::VideoWriter::fourcc('M','J','P','G');
cap.set(cv::CAP_PROP_FOURCC, fourcc);
// possible resolutions in JPEG coding
// (rows x columns) 320x640, 720x1280
cap.set(cv::CAP_PROP_FRAME_HEIGHT, 720);
cap.set(cv::CAP_PROP_FRAME_WIDTH, 1280);
cap.set(cv::CAP_PROP_FPS, 25);
// now the camera is ready for frame capture.
// debug print of accepted format:
union FourChar
{ // the four characters are coded into a 32 bit integer.
uint32_t cc4;
char ccc[4];
} fmt;
fmt.cc4 = cap.get(cv::CAP_PROP_FOURCC); // get format
printf("# Video device %d: width=%g, height=%g, format=%c%c%c%c, FPS=%g\n",
dev,
cap.get(cv::CAP_PROP_FRAME_WIDTH),
cap.get(cv::CAP_PROP_FRAME_HEIGHT),
fmt.ccc[0], fmt.ccc[1], fmt.ccc[2], fmt.ccc[3],
cap.get(cv::CAP_PROP_FPS));
}
