RV1126 NO.57：ROCKX+RV1126人脸识别推流项目之读取人脸图片并把特征值保存到sqlite3数据库-育师

一.本章节介绍

本章节将讲解如何使用rockx提取人脸图像特征值，并将其存储到sqlite3数据库中。在实际开发中，人脸特征值通常都会存入数据库，常见的选择包括sqlite3、MySQL等。（注：本项目不会深入讲解数据库知识，而是带大家完成基础的增删改查操作）。

二.rockx读取人脸特征值保存数据库大体框图

上图展示了将人脸特征和图片数据写入数据库的处理流程：

连接并读取人脸SQLite3数据库
初始化三个Rockx句柄：
- 人脸检测句柄(face_det_handle)
- 人脸识别句柄(face_recognize_handle)
- 人脸关键点句柄(face_5landmarks_handle)
使用rockx_image_read读取人脸图片
通过FILE API获取图片长度和二进制数据
使用rockx_face_align进行人脸图片对齐
调用rockx_face_recognize提取人脸特征值
将人脸特征值和图片二进制数据存入SQLite3数据库

三.rockx读取人脸特征值保存数据库的代码

3.1.Connection_sqlite3DataBase连接数据库

printf("Start Connection sqlite3......................\n"); Connection_sqlite3DataBase(); printf("End Connection_sqlite3DataBase......................\n");

这里封装了一个了SQLITE3连接数据库的函数Connection_sqlite3Database，这个函数的实现如下

int Connection_sqlite3DataBase() { rc = sqlite3_open("/userdata/face.db", &db); if (rc != SQLITE_OK) { fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db)); sqlite3_close(db); exit(1); } else { printf("You have opened a sqlite3 database named bind.db successfully!\nCongratulation! Have fun!\n"); } return 0; }

这个函数直接调用了sqlite3的api sqlite3_open来初始化人脸数据库，若返回值不等于SQLITE_OK则初始化数据库失败，否则就初始化成功。

3.2.创建三个rockx句柄

// 1. 创建人脸检测句柄 ret = rockx_create(&face_det_handle, ROCKX_MODULE_FACE_DETECTION_V2, config, 0); if (ret != ROCKX_RET_SUCCESS) { printf("init rockx module ROCKX_MODULE_FACE_DETECTION error %d\n", ret); return -1; } // 2. 创建人脸5关键点句柄 ret = rockx_create(&face_5landmarks_handle, ROCKX_MODULE_FACE_LANDMARK_5, config, 0); if (ret != ROCKX_RET_SUCCESS) { printf("init rockx module ROCKX_MODULE_FACE_LANDMARK_68 error %d\n", ret); return -1; } // 3. 创建人脸特征提取句柄 ret = rockx_create(&face_recognize_handle, ROCKX_MODULE_FACE_RECOGNIZE, config, 0); if (ret != ROCKX_RET_SUCCESS) { printf("init rockx module ROCKX_MODULE_FACE_LANDMARK_68 error %d\n", ret); return -1; }

我们需要创建三个人脸处理句柄来实现完整功能：

人脸检测句柄（ROCKX_MODULE_FACE_DETECTION_V2）
人脸识别句柄（ROCKX_MODULE_FACE_RECOGNIZE）
人脸关键点检测句柄（ROCKX_MODULE_FACE_LANDMARK_5）

这些句柄都通过rockx_create函数进行初始化。

3.3.读取人脸图片

rockx_image_t input_image1; rockx_image_read(image_path, &input_image1, 1); //读取图片文件到rockx_image_t（第二个参数1表示按RGB格式读取）

上图是读取人脸的图片，这里使用的是rockx_image_read来读取人脸图片，其中input_image是需要从命令行输入的。

3.4.使用FILE读取图片的二进制数据和长度

FILE *imageFile = fopen(image_path, "rb"); // 打开名为image.jpg的图片文件（二进制模式） if (!imageFile) { printf("无法打开图片文件.\n"); return -1; } fseek(imageFile, 0L, SEEK_END); // 定位到文件尾部 long fileSize = ftell(imageFile); // 获取文件大小 rewind(imageFile); // 重新定位到文件起始位置 printf("fileSize = %ld\n", fileSize); unsigned char *buffer = new unsigned char[fileSize]; // 分配足够大小的缓冲区 size_t bytesRead = fread(buffer, sizeof(unsigned char), fileSize, imageFile); // 从文件中读取图像数据到缓冲区

3.5.使用run_face_recognize检测人脸数据并找到最精确的人脸

int run_face_recognize(const char *name, rockx_image_t *in_image, rockx_face_feature_t *out_feature, unsigned char * buffer, int buffer_size) { rockx_ret_t ret; /*************** FACE Detect ***************/ // create rockx_face_array_t for store result rockx_object_array_t face_array; memset(&face_array, 0, sizeof(rockx_object_array_t)); // detect face ret = rockx_face_detect(face_det_handle, in_image, &face_array, NULL); if (ret != ROCKX_RET_SUCCESS) { printf("rockx_face_detect error %d\n", ret); return -1; } // process result for (int i = 0; i < face_array.count; i++) { int left = face_array.object[i].box.left; int top = face_array.object[i].box.top; int right = face_array.object[i].box.right; int bottom = face_array.object[i].box.bottom; float score = face_array.object[i].score; printf("%d box=(%d %d %d %d) score=%f\n", i, left, top, right, bottom,score); } rockx_object_t *max_face = get_max_face(&face_array); if (max_face == NULL) { printf("error no face detected\n"); return -1; } // Face Align rockx_image_t out_img; memset(&out_img, 0, sizeof(rockx_image_t)); /*************** 2. 人脸对齐 ***************/ ret = rockx_face_align(face_5landmarks_handle, in_image, &(max_face->box),NULL, &out_img); if (ret != ROCKX_RET_SUCCESS) { return -1; } /*************** 3. 人脸特征提取 ***************/ rockx_face_recognize(face_recognize_handle, &out_img, out_feature); /*************** 4. 特征+图片数据入库 ***************/ insert_face_data_toDataBase(name, out_feature->feature, FEATURE_SIZE, buffer, buffer_size); // Release Aligned Image rockx_image_release(&out_img); return 0; } run_face_recognize(name, &input_image1, &out_feature1, buffer, bytesRead);

rockx_object_t *get_max_face(rockx_object_array_t *face_array) { if (face_array->count == 0) { return NULL; } rockx_object_t *max_face = NULL;//存储人脸的最大指针 int i; for (i = 0; i < face_array->count; i++) { rockx_object_t *cur_face = &(face_array->object[i]); if (max_face == NULL) { max_face = cur_face; continue; } int cur_face_box_area = (cur_face->box.right - cur_face->box.left) * (cur_face->box.bottom - cur_face->box.top); int max_face_box_area = (max_face->box.right - max_face->box.left) * (max_face->box.bottom - max_face->box.top); if (cur_face_box_area > max_face_box_area) { max_face = cur_face; } } printf("get_max_face %d\n", i - 1); return max_face; }

get_max_face方法通过遍历所有人脸数据实现功能：计算每个人脸区域面积(cur_face_box_area)并与当前最大面积(max_face_box_area)比较。当检测到更大的人脸区域时，会更新最大面积值，最终确定max_face为最精确的人脸数据。

3.6. 把人脸特征值和图片数据保存到sqlite3数据库

void insert_face_data_toDataBase(const char *name, float feature[512], int featureSize, uint8_t *image_data, int image_length) { printf("face_size = %d\n", image_length); // 1. 预编译SQL并检查返回值 int ret = sqlite3_prepare(db, "insert into face_data_table(name,face_feature,feature_size,image_data,image_size) values (?,?,?,?,?);", -1, &stmt, NULL); if (ret != SQLITE_OK) { printf("sqlite3_prepare error: %s\n", sqlite3_errmsg(db)); return; } // 2. 绑定参数（修正特征字节数） ret = sqlite3_bind_text(stmt, 1, name, strlen(name), SQLITE_STATIC); // SQLITE_STATIC 等价于NULL，表示不释放 if (ret != SQLITE_OK) goto err; ret = sqlite3_bind_blob(stmt, 2, feature, featureSize * sizeof(float), SQLITE_STATIC); if (ret != SQLITE_OK) goto err; ret = sqlite3_bind_int(stmt, 3, featureSize); if (ret != SQLITE_OK) goto err; ret = sqlite3_bind_blob(stmt, 4, image_data, image_length, SQLITE_STATIC); if (ret != SQLITE_OK) goto err; ret = sqlite3_bind_int(stmt, 5, image_length); if (ret != SQLITE_OK) goto err; // 3. 打印调试 printf("insert face feature: "); for (int i = 0; i < 50; i++) { printf("%f ", feature[i]); } printf("\n"); // 4. 执行插入并检查返回值 ret = sqlite3_step(stmt); if (ret != SQLITE_DONE) { printf("sqlite3_step error: %s\n", sqlite3_errmsg(db)); } err: // 5. 释放语句对象 sqlite3_finalize(stmt); }

3.7.测试结果

(图二)

最后一步是将人脸特征值和图片数据存入SQLite3数据库。我们使用以下SQL插入语句：

INSERT INTO face_data_table(name, face_feature, feature_size, image_data, image_size) VALUES (?, ?, ?, ?, ?);

其中face_data_table是存储人脸数据的数据表，包含以下字段：

name：人脸名称
face_feature：人脸特征值
feature_size：特征值长度
image_data：图片数据
image_size：图片长度

通过sqlite3_prepare函数将SQL语句编译为可执行字节码，支持查询、插入、更新和删除等操作。具体参数绑定如下：

sqlite3_bind_text(stmt, 1, name, strlen(name), NULL)：绑定名称
sqlite3_bind_blob(stmt, 2, feature, featureSize, NULL)：绑定人脸特征值
sqlite3_bind_int(stmt, 3, featureSize)：绑定特征值长度
sqlite3_bind_blob(stmt, 4, image_data, image_length, NULL)：绑定图片数据
sqlite3_bind_int(stmt, 5, image_length)：绑定图片长度

3.8.完整代码

/* * ./sqlite3_operation_test name image_path */ #include "rockx.h" #include "sqlite3_operation.h" #define FEATURE_SIZE 512 rockx_handle_t face_det_handle; rockx_handle_t face_5landmarks_handle; rockx_handle_t face_recognize_handle; void insert_face_data_toDataBase(const char *name, float feature[512], int featureSize, uint8_t *image_data, int image_length) { printf("face_size = %d\n", image_length); // 1. 预编译SQL并检查返回值 int ret = sqlite3_prepare(db, "insert into face_data_table(name,face_feature,feature_size,image_data,image_size) values (?,?,?,?,?);", -1, &stmt, NULL); if (ret != SQLITE_OK) { printf("sqlite3_prepare error: %s\n", sqlite3_errmsg(db)); return; } // 2. 绑定参数（修正特征字节数） ret = sqlite3_bind_text(stmt, 1, name, strlen(name), SQLITE_STATIC); // SQLITE_STATIC 等价于NULL，表示不释放 if (ret != SQLITE_OK) goto err; ret = sqlite3_bind_blob(stmt, 2, feature, featureSize * sizeof(float), SQLITE_STATIC); if (ret != SQLITE_OK) goto err; ret = sqlite3_bind_int(stmt, 3, featureSize); if (ret != SQLITE_OK) goto err; ret = sqlite3_bind_blob(stmt, 4, image_data, image_length, SQLITE_STATIC); if (ret != SQLITE_OK) goto err; ret = sqlite3_bind_int(stmt, 5, image_length); if (ret != SQLITE_OK) goto err; // 3. 打印调试 printf("insert face feature: "); for (int i = 0; i < 50; i++) { printf("%f ", feature[i]); } printf("\n"); // 4. 执行插入并检查返回值 ret = sqlite3_step(stmt); if (ret != SQLITE_DONE) { printf("sqlite3_step error: %s\n", sqlite3_errmsg(db)); } err: // 5. 释放语句对象 sqlite3_finalize(stmt); } int Connection_sqlite3DataBase() { rc = sqlite3_open("/userdata/face.db", &db); if (rc != SQLITE_OK) { fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db)); sqlite3_close(db); exit(1); } else { printf("You have opened a sqlite3 database named bind.db successfully!\nCongratulation! Have fun!\n"); } return 0; } rockx_object_t *get_max_face(rockx_object_array_t *face_array) { if (face_array->count == 0) { return NULL; } rockx_object_t *max_face = NULL;//存储人脸的最大指针 int i; for (i = 0; i < face_array->count; i++) { rockx_object_t *cur_face = &(face_array->object[i]); if (max_face == NULL) { max_face = cur_face; continue; } int cur_face_box_area = (cur_face->box.right - cur_face->box.left) * (cur_face->box.bottom - cur_face->box.top); int max_face_box_area = (max_face->box.right - max_face->box.left) * (max_face->box.bottom - max_face->box.top); if (cur_face_box_area > max_face_box_area) { max_face = cur_face; } } printf("get_max_face %d\n", i - 1); return max_face; } int run_face_recognize(const char *name, rockx_image_t *in_image, rockx_face_feature_t *out_feature, unsigned char * buffer, int buffer_size) { rockx_ret_t ret; /*************** FACE Detect ***************/ // create rockx_face_array_t for store result rockx_object_array_t face_array; memset(&face_array, 0, sizeof(rockx_object_array_t)); // detect face ret = rockx_face_detect(face_det_handle, in_image, &face_array, NULL); if (ret != ROCKX_RET_SUCCESS) { printf("rockx_face_detect error %d\n", ret); return -1; } // process result for (int i = 0; i < face_array.count; i++) { int left = face_array.object[i].box.left; int top = face_array.object[i].box.top; int right = face_array.object[i].box.right; int bottom = face_array.object[i].box.bottom; float score = face_array.object[i].score; printf("%d box=(%d %d %d %d) score=%f\n", i, left, top, right, bottom,score); } rockx_object_t *max_face = get_max_face(&face_array); if (max_face == NULL) { printf("error no face detected\n"); return -1; } // Face Align rockx_image_t out_img; memset(&out_img, 0, sizeof(rockx_image_t)); /*************** 2. 人脸对齐 ***************/ ret = rockx_face_align(face_5landmarks_handle, in_image, &(max_face->box),NULL, &out_img); if (ret != ROCKX_RET_SUCCESS) { return -1; } /*************** 3. 人脸特征提取 ***************/ rockx_face_recognize(face_recognize_handle, &out_img, out_feature); /*************** 4. 特征+图片数据入库 ***************/ insert_face_data_toDataBase(name, out_feature->feature, FEATURE_SIZE, buffer, buffer_size); // Release Aligned Image rockx_image_release(&out_img); return 0; } int main(int argc, char *argv[]) { rockx_ret_t ret; printf("----------------- main init ---------------------\n"); #if 1 if (argc != 3) { printf("Usage: Insert DataBase ./sqlite3_operation_test name image_path\n"); return -1; } printf("Start Connection sqlite3......................\n"); Connection_sqlite3DataBase(); printf("End Connection_sqlite3DataBase......................\n"); // 创建rockx配置对象 rockx_config_t *config = rockx_create_config(); // 设置rockx模型数据路径（需提前放置模型文件） rockx_add_config(config, ROCKX_CONFIG_DATA_PATH, "/userdata/rockx_data/"); /*************** Creat Handle ***************/ // create a face detection handle // 1. 创建人脸检测句柄 ret = rockx_create(&face_det_handle, ROCKX_MODULE_FACE_DETECTION_V2, config, 0); if (ret != ROCKX_RET_SUCCESS) { printf("init rockx module ROCKX_MODULE_FACE_DETECTION error %d\n", ret); return -1; } // 2. 创建人脸5关键点句柄 ret = rockx_create(&face_5landmarks_handle, ROCKX_MODULE_FACE_LANDMARK_5, config, 0); if (ret != ROCKX_RET_SUCCESS) { printf("init rockx module ROCKX_MODULE_FACE_LANDMARK_68 error %d\n", ret); return -1; } // 3. 创建人脸特征提取句柄 ret = rockx_create(&face_recognize_handle, ROCKX_MODULE_FACE_RECOGNIZE, config, 0); if (ret != ROCKX_RET_SUCCESS) { printf("init rockx module ROCKX_MODULE_FACE_LANDMARK_68 error %d\n", ret); return -1; } const char *name = argv[1]; const char *image_path = argv[2]; rockx_face_feature_t out_feature1; rockx_image_t input_image1; rockx_image_read(image_path, &input_image1, 1); //读取图片文件到rockx_image_t（第二个参数1表示按RGB格式读取） FILE *imageFile = fopen(image_path, "rb"); // 打开名为image.jpg的图片文件（二进制模式） if (!imageFile) { printf("无法打开图片文件.\n"); return -1; } fseek(imageFile, 0L, SEEK_END); // 定位到文件尾部 long fileSize = ftell(imageFile); // 获取文件大小 rewind(imageFile); // 重新定位到文件起始位置 printf("fileSize = %ld\n", fileSize); unsigned char *buffer = new unsigned char[fileSize]; // 分配足够大小的缓冲区 size_t bytesRead = fread(buffer, sizeof(unsigned char), fileSize, imageFile); // 从文件中读取图像数据到缓冲区 /*************** 执行人脸处理+入库 ***************/ run_face_recognize(name, &input_image1, &out_feature1, buffer, bytesRead); #endif return 0; }