树莓派可以通过加入 参数 “bayer=True” ，来获取CSI相机的raw图片，raw数据会紧跟在jpg图片的末尾，具体提取的方法不在累述，可以方便的google到。而Nvidia的 Jetson nano要获取raw图片的方法网上比较零散，故整理了一下。
获取raw图片的方法其实比较简单，使用的是jetson nano中自带的Libargus api。其api介绍可以参考https://docs.nvidia.com/jetson/l4t-multimedia/group__LibargusAPI.html,api架构可以参考https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3231/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide/jetson_xavier_camera_soft_archi.html
相关代码在 Libargus api demo中的 argus\samples\oneShot 简单修改而来。并增加了转换为opencvmat的代码
主要更改的地方
1. iEGLStreamSettings->setPixelFormat(Argus::PIXEL_FMT_YCbCr_420_888); 变更为
iEGLStreamSettings->setPixelFormat(Argus::PIXEL_FMT_RAW16);
2. EGLStream::IImageJPEG *iImageJPEG = Argus::interface_cast(image);变更为
EGLStream::IImage *iImage = Argus::interface_cast(image);
3. 转换的代码看代码里的注释
#include <stdio.h>
#include <stdlib.h>
#include <Argus/Argus.h>
#include <EGLStream/EGLStream.h>
#include "ArgusHelpers.h"
#include "CommonOptions.h"
#include <opencv2/imgcodecs.hpp>
#define EXIT_IF_NULL(val,msg) \
{if (!val) {printf("%s\n",msg); return EXIT_FAILURE;}}
#define EXIT_IF_NOT_OK(val,msg) \
{if (val!=Argus::STATUS_OK) {printf("%s\n",msg); return EXIT_FAILURE;}}
#ifdef ANDROID
#define FILE_PREFIX "/sdcard/DCIM/"
#else
#define FILE_PREFIX ""
#endif
int main(int argc, char** argv)
{
ArgusSamples::CommonOptions options(basename(argv[0]),
ArgusSamples::CommonOptions::Option_D_CameraDevice |
ArgusSamples::CommonOptions::Option_M_SensorMode);
if (!options.parse(argc, argv))
return EXIT_FAILURE;
if (options.requestedExit())
return EXIT_SUCCESS;
const uint64_t FIVE_SECONDS_IN_NANOSECONDS = 5000000000;
Argus::UniqueObj<Argus::CameraProvider> cameraProvider(Argus::CameraProvider::create());
Argus::ICameraProvider *iCameraProvider =
Argus::interface_cast<Argus::ICameraProvider>(cameraProvider);
EXIT_IF_NULL(iCameraProvider, "Cannot get core camera provider interface");
printf("Argus Version: %s\n", iCameraProvider->getVersion().c_str());
Argus::CameraDevice *device = ArgusSamples::ArgusHelpers::getCameraDevice(
cameraProvider.get(), options.cameraDeviceIndex());
Argus::ICameraProperties *iCameraProperties =
Argus::interface_cast<Argus::ICameraProperties>(device);
if (!iCameraProperties)
{
REPORT_ERROR("Failed to get ICameraProperties interface");
return EXIT_FAILURE;
}
Argus::SensorMode* sensorMode = ArgusSamples::ArgusHelpers::getSensorMode(
device, options.sensorModeIndex());
Argus::ISensorMode *iSensorMode =
Argus::interface_cast<Argus::ISensorMode>(sensorMode);
if (!iSensorMode)
{
REPORT_ERROR("Failed to get sensor mode interface");
return EXIT_FAILURE;
}
printf("Capturing from device %d using sensor mode %d (%dx%d)\n",
options.cameraDeviceIndex(), options.sensorModeIndex(),
iSensorMode->getResolution().width(), iSensorMode->getResolution().height());
Argus::Status status;
Argus::UniqueObj<Argus::CaptureSession> captureSession(
iCameraProvider->createCaptureSession(device, &status));
EXIT_IF_NOT_OK(status, "Failed to create capture session");
Argus::ICaptureSession *iSession =
Argus::interface_cast<Argus::ICaptureSession>(captureSession);
EXIT_IF_NULL(iSession, "Cannot get Capture Session Interface");
Argus::UniqueObj<Argus::OutputStreamSettings> streamSettings(
iSession->createOutputStreamSettings(Argus::STREAM_TYPE_EGL));
Argus::IEGLOutputStreamSettings *iEGLStreamSettings =
Argus::interface_cast<Argus::IEGLOutputStreamSettings>(streamSettings);
EXIT_IF_NULL(iEGLStreamSettings, "Cannot get IEGLOutputStreamSettings Interface");
iEGLStreamSettings->setPixelFormat(Argus::PIXEL_FMT_RAW16);
iEGLStreamSettings->setResolution(iSensorMode->getResolution());
iEGLStreamSettings->setMetadataEnable(true);
Argus::UniqueObj<Argus::OutputStream> stream(
iSession->createOutputStream(streamSettings.get()));
EXIT_IF_NULL(stream, "Failed to create EGLOutputStream");
Argus::UniqueObj<EGLStream::FrameConsumer> consumer(
EGLStream::FrameConsumer::create(stream.get()));
EGLStream::IFrameConsumer *iFrameConsumer =
Argus::interface_cast<EGLStream::IFrameConsumer>(consumer);
EXIT_IF_NULL(iFrameConsumer, "Failed to initialize Consumer");
Argus::UniqueObj<Argus::Request> request(
iSession->createRequest(Argus::CAPTURE_INTENT_STILL_CAPTURE));
Argus::IRequest *iRequest = Argus::interface_cast<Argus::IRequest>(request);
EXIT_IF_NULL(iRequest, "Failed to get capture request interface");
status = iRequest->enableOutputStream(stream.get());
EXIT_IF_NOT_OK(status, "Failed to enable stream in capture request");
Argus::ISourceSettings *iSourceSettings =
Argus::interface_cast<Argus::ISourceSettings>(request);
EXIT_IF_NULL(iSourceSettings, "Failed to get source settings request interface");
iSourceSettings->setSensorMode(sensorMode);
uint32_t requestId = iSession->capture(request.get());
EXIT_IF_NULL(requestId, "Failed to submit capture request");
Argus::UniqueObj<EGLStream::Frame> frame(
iFrameConsumer->acquireFrame(FIVE_SECONDS_IN_NANOSECONDS, &status));
EGLStream::IFrame *iFrame = Argus::interface_cast<EGLStream::IFrame>(frame);
EXIT_IF_NULL(iFrame, "Failed to get IFrame interface");
EGLStream::Image *image = iFrame->getImage();
EXIT_IF_NULL(image, "Failed to get Image from iFrame->getImage()");
EGLStream::IImage *iImage = Argus::interface_cast<EGLStream::IImage>(image);
EXIT_IF_NULL(iImage, "Failed to get iImage Interface");
//转换为opencvmat，我使用的是12.3m的相机，分辨率为4320*3040，每行的pitch为8192
//pitch大小可以在通过sensorMode读出，我就不在写代码了。
Mat _img(3040,4032,CV_16UC1); //初始化一个mat
uint16_t* p_s = (uint16_t*)iImage->mapBuffer(); //相机buffer指针
uint16_t* p_d = (uint16_t*)_img.data; //Mat指针
p_d+=(3040*4032 - 1);//由于相机buffer图像是翻转了180度的，我在赋值到Mat时顺便翻转回去了
for(int y=0;y<3040;y++){
for(int x =0;x<4032;x++){
// 12.3m相机是12bit深度的图片，相机buffer内是14bit的，所以进行了移位运算，不知是不是驱动有bug的原因
*p_d = *p_s>>2;
if(y%2==0 && x%2==0){
//这一步是12.3m相机red通道raw值不仅低，故赋值时增加了1倍，这样转换后的彩色图更加接近真实一点
*p_d = *p_d *2;
}
p_d--;
p_s++;
}
p_s+=64;
}
//这里保存的是bayer图，如果想看转换后的图，可以通过opencv里的cvtcolor函数进行bayer格式的转换
imwrite("bayer".tif,_img);
// Shut down Argus.
cameraProvider.reset();
return EXIT_SUCCESS;
}