Qt C++与Halcon联合开发实现简易OCR字符识别
效果图如下：
原图像
识别后的图像(窗体左上角为识别的字符)
一、开发平台搭建：
本人用开发平台如下:
1> Visual Studio 2017
2> Qt5.12(包含MVSC编译器)
3> Halcon18.05-64Bit
二、Qt项目的创建
1>新建Qt Widget项目>>选择MainWindow类>>选择MSVC2017编译器进行源码编译。
2>打开Halcon的安装目录，找到并拷贝lib和include文件夹到所创建的Qt项目文件夹中。
3>在Qt项目.pro文件夹中添加如下代码，用于包含与Halcon相关的C++头文件和lib库。
4>打开Qt项目中的.ui文件，创建一个QWidget控件至主界面，在菜单栏添加采集和字符识别按钮。
三、 程式编写
1.Qt C++代码：
1> 创建Halcon窗体相关的类(该类源码参考Halcon自带的Qt开发例程)：
QHalconWindow类：
头文件：
#ifndef QHALCONWINDOW_H
#define QHALCONWINDOW_H
#include 源文件：
#include "qhalconwindow.h"
Herror __stdcall ContentUpdateCallback(void* context)
{
QHalconWindow* hwindow = (QHalconWindow*)context;
hwindow->update();
return H_MSG_OK;
}
QHalconWindow::QHalconWindow(QWidget *parent, long width, long height) : QWidget(parent)
{
show();
resize(width, height);
halconBuffer.reset(new HalconCpp::HWindow(0, 0, 200, 100, 0, "buffer", ""));
halconBuffer->SetWindowParam("graphics_stack", "true");
halconBuffer->SetWindowParam("flush", "false");
halconBuffer->SetContentUpdateCallback((void*)&ContentUpdateCallback, this);
}
void QHalconWindow::resizeEvent(QResizeEvent *event)
{
Q_UNUSED(event);
halconBuffer->SetWindowExtents(0, 0, width(), height());
halconBuffer->FlushBuffer();
}
void QHalconWindow::paintEvent(QPaintEvent *event)
{
Q_UNUSED(event);
HString type;
Hlong width, height;
HImage image = halconBuffer->DumpWindowImage();
HImage imageInterleaved = image.InterleaveChannels("argb", "match", 0);
unsigned char* pointer = (unsigned char*)imageInterleaved.GetImagePointer1(&type, &width, &height);
QImage qimage(pointer, width/4, height, QImage::Format_RGB32);
QPainter painter(this);
painter.drawImage(QPoint(0, 0), qimage);
}
void QHalconWindow::mouseMoveEvent(QMouseEvent *event)
{
Q_UNUSED(event);
if ((event->buttons() == Qt::LeftButton) && lastMousePos.x() != -1)
{
QPoint delta = lastMousePos - event->globalPos();
double scalex = (lastCol2 - lastCol1 + 1) / (double)width();
double scaley = (lastRow2 - lastRow1 + 1) / (double)height();
try
{
SetPartFloat(lastRow1 + (delta.y() * scaley),
lastCol1 + (delta.x() * scalex),
lastRow2 + (delta.y() * scaley),
lastCol2 + (delta.x() * scalex));
halconBuffer->FlushBuffer();
}
catch (HalconCpp::HOperatorException)
{
}
}
}
void QHalconWindow::mousePressEvent(QMouseEvent *event)
{
Q_UNUSED(event);
GetPartFloat(&lastRow1, &lastCol1, &lastRow2, &lastCol2);
lastMousePos = event->globalPos();
}
void QHalconWindow::mouseReleaseEvent(QMouseEvent *event)
{
Q_UNUSED(event);
lastMousePos = QPoint(-1, -1);
}
void QHalconWindow::mouseDoubleClickEvent(QMouseEvent *event)
{
Q_UNUSED(event);
if (event->buttons() == Qt::LeftButton)
{
halconBuffer->SetPart(0, 0, -1, -1);
halconBuffer->FlushBuffer();
}
}
void QHalconWindow::wheelEvent(QWheelEvent *event)
{
Q_UNUSED(event);
int num_notch = std::abs(event->delta()) / 120;
double factor = (event->delta() > 0) ? std::sqrt(2.0) : 1.0 / std::sqrt(2.0);
while (num_notch > 1)
{
factor = factor * ((event->delta() > 0) ? std::sqrt(2.0) : 1.0 / std::sqrt(2.0));
num_notch--;
}
double centerRow, centerCol;
halconBuffer->ConvertCoordinatesWindowToImage(event->y(), event->x(), ¢erRow, ¢erCol);
double row1, col1, row2, col2;
GetPartFloat(&row1, &col1, &row2, &col2);
double left = centerRow - row1;
double right = row2 - centerRow;
double top = centerCol - col1;
double buttom = col2 - centerCol;
double newRow1 = centerRow - left * factor;
double newRow2 = centerRow + right * factor;
double newCol1 = centerCol - top * factor;
double newCol2 = centerCol + buttom * factor;
try
{
SetPartFloat(newRow1, newCol1, newRow2, newCol2);
halconBuffer->FlushBuffer();
}
catch (HalconCpp::HOperatorException)
{
}
}
void QHalconWindow::GetPartFloat(double *row1, double *col1, double *row2, double *col2)
{
HalconCpp::HTuple trow1, tcol1, trow2, tcol2;
halconBuffer->GetPart(&trow1, &tcol1, &trow2, &tcol2);
*row1 = trow1.D();
*col1 = tcol1.D();
*row2 = trow2.D();
*col2 = tcol2.D();
}
void QHalconWindow::SetPartFloat(double row1, double col1, double row2, double col2)
{
halconBuffer->SetPart(HalconCpp::HTuple(row1), HalconCpp::HTuple(col1),
HalconCpp::HTuple(row2), HalconCpp::HTuple(col2));
}
2>项目中的MainWindow类:
MainWindow类：
头文件：
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include 源文件：
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include 2、Halcon代码：
//*打开窗体、读取图像
dev_close_window ()
read_image (Image, 'C:/OCR/Image 08.bmp')
get_image_size (Image, Width, Height)
dev_open_window (0, 0, Width, Height, 'black', WindowHandle)
dev_display (Image)
//*获取字符区域、计算区域中心位置和区域的角度
threshold (Image, Regions, 3, 100)
closing_rectangle1 (Regions, RegionClosing, 3, 3)
connection (RegionClosing, ConnectedRegions)
select_shape (ConnectedRegions, SelectedRegions, ['height','width'], 'and', [42.431,25.367], [47.661,31.514])
union1 (SelectedRegions, RegionUnion)
smallest_rectangle2 (RegionUnion, Row, Column, Phi, Length1, Length2)
gen_rectangle2 (Rectangle, Row, Column, Phi, Length1, Length2)
area_center (Rectangle, Area, Row1, Column1)
//*将图片中的字符区域移动到窗体中央
vector_angle_to_rigid (Row1, Column1, Phi, Height/2, Width/2, 0, HomMat2D)
affine_trans_image (Image, ImageAffineTrans, HomMat2D, 'constant', 'false')
affine_trans_region (Rectangle, RegionAffineTrans, HomMat2D, 'nearest_neighbor')
//*显示截取的字符区域
reduce_domain (ImageAffineTrans, RegionAffineTrans, ImageReduced)
dev_display (ImageReduced)
//*读取字符
create_text_model_reader ('auto', 'Universal_Rej.occ', TextModel)
find_text (ImageReduced, TextModel, TextResultID)
get_text_object (Characters, TextResultID, 'all_lines')
smallest_rectangle2 (RegionAffineTrans, Row2, Column2, Phi1, Length11, Length21)
get_text_result (TextResultID, 'class', ResultValue)
tuple_sum (ResultValue, Sum)
四、用到的字符图片
