From 278f64148595c297a1ed8e06de1028a062d17459 Mon Sep 17 00:00:00 2001 From: josh Date: Wed, 12 Aug 2009 03:49:29 +0000 Subject: [PATCH] added BMP class to write a test image - image capturing working!! git-svn-id: svn://anubis/misc/WebcamTracker@128 bd8a9e45-a331-0410-811e-c64571078777 --- BMP.cc | 127 +++++++++++++++++++++++++++++++++++++++++++++++ BMP.h | 54 ++++++++++++++++++++ WebcamTracker.cc | 22 +++++++- 3 files changed, 202 insertions(+), 1 deletion(-) create mode 100644 BMP.cc create mode 100644 BMP.h diff --git a/BMP.cc b/BMP.cc new file mode 100644 index 0000000..685d240 --- /dev/null +++ b/BMP.cc @@ -0,0 +1,127 @@ +// BMP.cc +// extracts/inserts data from/into .bmp file +// Adapted by Josh Holtrop from the original access_bmp.c by gw +// Supports reading and creating 24-bit color BMP images + +#include "BMP.h" +#include +#include +using namespace std; + +BMP::BMP(const char * fileName) +{ + open(fileName); +} + +BMP::BMP(const char * fileName, int width, int height, unsigned char * data) +{ + create(fileName, width, height, data); +} + +BMP::~BMP() +{ + if (m_fp != NULL) + close(); +} + +bool BMP::open(const char * fileName) +{ + size_t bytes_read; + m_fp = fopen(fileName, "r+"); + if (m_fp != NULL) + { + // read file header + bytes_read = fread(&m_header, sizeof(m_header), 1, m_fp); + if (m_header.id[0] != 'B' || m_header.id[1] != 'M') + { + cerr << fileName << " does not appear to be a BMP file." << endl; + fclose(m_fp); + m_fp = NULL; + } + // read image information + bytes_read = fread(&m_info, sizeof(m_info), 1, m_fp); + } + return (m_fp != NULL); +} + +bool BMP::create(const char * fileName, int width, int height, + unsigned char * data) +{ + size_t bytes_written; + m_fp = fopen(fileName, "w+"); + if (m_fp != NULL) + { + /* Initialize the header structure */ + m_header.id[0] = 'B'; + m_header.id[1] = 'M'; + int row_padding = (3 * width) & 0x3; + if (row_padding) + row_padding = 4 - row_padding; + int row_bytes = (3 * width) + row_padding; + m_header.file_size = sizeof(m_header) + + sizeof(m_info) + + row_bytes * height; + m_header.reserved = 0; + m_header.offset = sizeof(m_header) + sizeof(m_info); + + /* Initialize the information structure */ + m_info.header_size = 40; + m_info.width = width; + m_info.height = height; + m_info.color_planes = 1; + m_info.color_depth = 24; + m_info.compression = 0; + m_info.image_size = 0; + m_info.xresolution = 2835; + m_info.yresolution = 2835; + m_info.num_colors = 0; + m_info.num_important_colors = 0; + + /* write them to the file */ + bytes_written = fwrite(&m_header, sizeof(m_header), 1, m_fp); + bytes_written = fwrite(&m_info, sizeof(m_info), 1, m_fp); + + unsigned int zero = 0; + unsigned char * data_ptr = data + (3 * width) * (height - 1); + for (int i = 0; i < height; i++) + { + bytes_written = fwrite(data_ptr, 3 * width, 1, m_fp); + if (row_padding) + bytes_written = fwrite(&zero, row_padding, 1, m_fp); + data_ptr -= 3 * width; + } + } + return (m_fp != NULL); +} + +void BMP::read(unsigned char * buf) +{ + size_t bytes_read; + if (m_fp != NULL) + { + int row_data_bytes = 3 * m_info.width; + int row_padding = row_data_bytes & 0x3; + if (row_padding) + row_padding = 4 - row_padding; + fseek(m_fp, + (m_header.offset != 0 + ? m_header.offset + : sizeof(m_header) + sizeof(m_info)), + SEEK_SET); + unsigned char * data_ptr = buf + row_data_bytes * (m_info.height - 1); + for (int i = 0; i < m_info.height; i++) + { + bytes_read = fread(data_ptr, row_data_bytes, 1, m_fp); + if (row_padding) + fseek(m_fp, row_padding, SEEK_CUR); + data_ptr -= row_data_bytes; + } + } +} + +void BMP::close() +{ + if (m_fp != NULL) + fclose(m_fp); + m_fp = NULL; +} diff --git a/BMP.h b/BMP.h new file mode 100644 index 0000000..d4878dc --- /dev/null +++ b/BMP.h @@ -0,0 +1,54 @@ +// BMP.h +// extracts/inserts data from/into .bmp file +// Adapted by Josh Holtrop from the original access_bmp.c by gw +// Supports reading and creating 24-bit color BMP images + +#include + +#define BMP_RED 2 +#define BMP_GREEN 1 +#define BMP_BLUE 0 + +class BMP +{ +public: + typedef struct + { + char id[2]; + int file_size; + int reserved; + int offset; + } __attribute__ ((packed)) header_t; + + typedef struct + { + int header_size; + int width; + int height; + unsigned short int color_planes; + unsigned short int color_depth; + unsigned int compression; + int image_size; + int xresolution; + int yresolution; + int num_colors; + int num_important_colors; + } __attribute__ ((packed)) info_t; + + BMP(const char * fileName); + BMP(const char * fileName, int width, int height, unsigned char * data); + ~BMP(); + void read(unsigned char * buf); + int getWidth() { return m_info.width; } + int getHeight() { return m_info.height; } + +protected: + FILE * m_fp; + header_t m_header; + info_t m_info; + + bool open(const char * fileName); + bool create(const char * fileName, int width, int height, + unsigned char * data); + void close(); +}; diff --git a/WebcamTracker.cc b/WebcamTracker.cc index a08d3d7..0c2e4d9 100644 --- a/WebcamTracker.cc +++ b/WebcamTracker.cc @@ -11,6 +11,7 @@ #include /* memset() */ #include #include "WebcamTracker.h" +#include "BMP.h" using namespace std; int main(int argc, char * argv[]) @@ -59,7 +60,9 @@ bool WebcamTracker::open(const char * device) void WebcamTracker::start() { - setFormat(640, 480); + int width = 640; + int height = 480; + setFormat(width, height); requestBuffers(20); for (int i = 0; i < m_numbufs; i++) { @@ -67,9 +70,26 @@ void WebcamTracker::start() queueBuffer(i); } beginStreaming(); + v4l2_buffer buf; dequeueBuffer(&buf); endStreaming(); + + /* do something with the image referenced by buf */ + unsigned char * image_data = (unsigned char *) m_buffers[buf.index]; + unsigned char * bmp_data = new unsigned char[width * height * 3]; + for (int j = 0; j < height; j++) + { + for (int k = 0; k < width; k++) + { + unsigned char y = image_data[(width * j + k) * 2]; + bmp_data[width * j * 3 + k * 3] = y; + bmp_data[width * j * 3 + k * 3 + 1] = y; + bmp_data[width * j * 3 + k * 3 + 2] = y; + } + } + BMP bmp("webcam.bmp", width, height, bmp_data); + delete bmp_data; } void WebcamTracker::requestBuffers(int num)