Lepton 3.5热像仪图像质量问题[在Jetson Nano上运行]

如何解决Lepton 3.5热像仪图像质量问题[在Jetson Nano上运行]

我正在使用Lepton 3.5和Pure-thermal2。在Jetson Nano上来自Groupgets git页面：https://github.com/groupgets/purethermal1-uvc-capture的已编译C + V4l2代码。

最初收到此错误消息Libv4l不接受RGB24格式。无法继续。然后将图像分辨率从80x60更改为160x120，并将像素格式YUYV更改为UYVY，然后代码可以工作，但无法生成良好的图像。图像包含多个具有不同颜色的条带，如下所示：

将像素格式更改为灰色，分辨率为640 * 480，生成如下图所示的图像：

请任何人建议如何以GREY，UYVY和其他受支持的格式获取完美的图像。

    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <fcntl.h>
    #include <errno.h>
    #include <sys/ioctl.h>
    #include <sys/types.h>
    #include <sys/time.h>
    #include <sys/mman.h>
    #include <linux/videodev2.h>
    #include <libv4l2.h>
    
    #define CLEAR(x) memset(&(x),sizeof(x))
    
    struct buffer {
            void   *start;
            size_t length;
    };
    
    static void xioctl(int fh,int request,void *arg)
    {
            int r;
    
            do {
                    r = v4l2_ioctl(fh,request,arg);
            } while (r == -1 && ((errno == EINTR) || (errno == EAGAIN)));
    
            if (r == -1) {
                    fprintf(stderr,"error %d,%s\n",errno,strerror(errno));
                    exit(EXIT_FAILURE);
            }
    }

    int main(int argc,char **argv)
    {
            struct v4l2_format              fmt;
            struct v4l2_buffer              buf;
            struct v4l2_requestbuffers      req;
            enum v4l2_buf_type              type;
            fd_set                          fds;
            struct timeval                  tv;
            int                             r,fd = -1;
            unsigned int                    i,n_buffers;
            char                            *dev_name = "/dev/video0";
            char                            out_name[256];
            FILE                            *fout;
            struct buffer                   *buffers;
    
            fd = v4l2_open(dev_name,O_RDWR | O_NONBLOCK,0);
            if (fd < 0) {
                    perror("Cannot open device");
                    exit(EXIT_FAILURE);
    }       

            CLEAR(fmt);
            fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
            fmt.fmt.pix.width       = 640;
            fmt.fmt.pix.height      = 480;
            fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_GREY;
            fmt.fmt.pix.field       = V4L2_FIELD_NONE;
            xioctl(fd,VIdioC_S_FMT,&fmt);
            if (fmt.fmt.pix.pixelformat != V4L2_PIX_FMT_GREY) {
                    printf("Libv4l didn't accept RGB24 format. Can't proceed.\n");
                    exit(EXIT_FAILURE);
            }
            if ((fmt.fmt.pix.width != 80) || (fmt.fmt.pix.height != 60))
                    printf("Warning: driver is sending image at %dx%d\n",fmt.fmt.pix.width,fmt.fmt.pix.height);

            CLEAR(req);
            req.count = 2;
            req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
            req.memory = V4L2_MEMORY_MMAP;
            xioctl(fd,VIdioC_REQBUFS,&req);
    
            buffers = calloc(req.count,sizeof(*buffers));
            for (n_buffers = 0; n_buffers < req.count; ++n_buffers) {
                    CLEAR(buf);

                    buf.type        = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                    buf.memory      = V4L2_MEMORY_MMAP;
                    buf.index       = n_buffers;
    
                    xioctl(fd,VIdioC_QUERYBUF,&buf);

                    buffers[n_buffers].length = buf.length;
                    buffers[n_buffers].start = v4l2_mmap(NULL,buf.length,PROT_READ | PROT_WRITE,MAP_SHARED,fd,buf.m.offset);

                    if (MAP_Failed == buffers[n_buffers].start) {
                            perror("mmap");
                            exit(EXIT_FAILURE);
                    }
            }

            for (i = 0; i < n_buffers; ++i) {
                    CLEAR(buf);
                    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                    buf.memory = V4L2_MEMORY_MMAP;
                    buf.index = i;
                    xioctl(fd,VIdioC_QBUF,&buf);
            }
            type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

            xioctl(fd,VIdioC_STREAMON,&type);
            for (i = 0; i < 20; i++) {
                    do {
                            FD_ZERO(&fds);
                            FD_SET(fd,&fds);
    
                            /* Timeout. */
                            tv.tv_sec = 2;
                            tv.tv_usec = 0;

                            r = select(fd + 1,&fds,NULL,&tv);
                    } while ((r == -1 && (errno = EINTR)));
                    if (r == -1) {
                            perror("select");
                            return errno;
                    }
    
                    CLEAR(buf);
                    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                    buf.memory = V4L2_MEMORY_MMAP;
                    xioctl(fd,VIdioC_DQBUF,&buf);

                    sprintf(out_name,"out%03d.ppm",i);
                    fout = fopen(out_name,"w");
                    if (!fout) {
                            perror("Cannot open image");
                            exit(EXIT_FAILURE);
                    }
                    fprintf(fout,"P6\n%d %d 255\n",fmt.fmt.pix.height);
                    fwrite(buffers[buf.index].start,buf.bytesused,1,fout);
                    fclose(fout);

                    xioctl(fd,&buf);
            }

            type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
            xioctl(fd,VIdioC_STREAMOFF,&type);
            for (i = 0; i < n_buffers; ++i)
                    v4l2_munmap(buffers[i].start,buffers[i].length);
            v4l2_close(fd);
    
            return 0;
    }

解决方法

您是否检查过 USB 描述符？ 纯热固件创建一个 uvc 设备，使用 lsusb，您可以获得 USB 描述符中支持的格式和帧的列表。