diff --git a/src/ScanFormWidget.cpp b/src/ScanFormWidget.cpp
index 74733f4..8950727 100644
--- a/src/ScanFormWidget.cpp
+++ b/src/ScanFormWidget.cpp
@@ -133,20 +133,25 @@ ScanFormWidget::ScanFormWidget(QWidget *parent) : TabFormWidget(parent) {
     connect(EventCenter::Default(),&EventCenter::ResponsePreview,[=](QObject* sender,QObject* data){
         setPreviewing(true);
     });
+
     connect(EventCenter::Default(),&EventCenter::ResponsePreviewData,[=](QObject* sender,QObject* data){
         if (!data)return;
+        static const size_t Row = 140;
+        static const size_t Col = 140;
+        static const float pixelSpacing = 1.5f;
+        static const float halfROIWidth = 100.0f;
         QByteArray* array = (QByteArray*)data;
         uchar* raw_dataptr = (uchar*)array->data();
-        uchar c_data[200][200];
+        uchar c_data[Row][Col];
         uchar* data_ptr = c_data[0];
-        for(int i=0;i<200;i++){
+        for(int i=0;i<Row;i++){
             data_ptr = c_data[i];
-            memcpy(data_ptr,raw_dataptr,200);
-            raw_dataptr += 200;
+            memcpy(data_ptr,raw_dataptr,Col);
+            raw_dataptr += Col;
 
         }
         raw_dataptr = (uchar*)array->data();
-        QImage img(c_data[0] , 200, 200, QImage::Format_Grayscale8);
+        QImage img(c_data[0] , Col, Row, QImage::Format_Grayscale8);
         viewer->setFixedSize(800,800);
         QPixmap pic = QPixmap::fromImage(img).scaledToHeight(800,Qt::SmoothTransformation);
         QPainter painter(&pic);
@@ -159,18 +164,19 @@ ScanFormWidget::ScanFormWidget(QWidget *parent) : TabFormWidget(parent) {
         font.setBold(true);
         painter.setFont(font);
         painter.setPen(pen);
-        painter.drawLine(29*4,29*4,29*4,171*4);
-        painter.drawLine(29*4+1,29*4,171*4,29*4);
-        painter.drawLine(29*4+1,171*4,171*4,171*4);
-        painter.drawLine(171*4,29*4+1,171*4,171*4-1);
+        static int borderSpacing = round(((pixelSpacing*(Row*0.5f)-halfROIWidth)*(800.0f/(1.5f*140.0f))));
+        painter.drawLine(borderSpacing,borderSpacing,borderSpacing,800-borderSpacing);
+        painter.drawLine(borderSpacing+1,borderSpacing,800-borderSpacing,borderSpacing);
+        painter.drawLine(borderSpacing+1,800-borderSpacing,800-borderSpacing,800-borderSpacing);
+        painter.drawLine(800-borderSpacing,borderSpacing+1,800-borderSpacing,800-borderSpacing-1);
         pen.setColor(QColor(255,255,0));
         painter.setPen(pen);
-        painter.drawText(335,40,"Previewing");
-        painter.drawText(29*3,400-13,"R");
-        painter.drawText(800-29*3-13,400-13,"L");
-        painter.drawText(400-13,29*3+13,"H");
-        painter.drawText(400-13,800-29*3+13,"F");
-        painter.drawText(29*4,29*4-2,"ROI");
+//        painter.drawText(335,40,"Previewing");
+        painter.drawText(borderSpacing+13,400+13,"R");
+        painter.drawText(800-borderSpacing-30,400+13,"L");
+        painter.drawText(400-13,borderSpacing+30,"H");
+        painter.drawText(400-13,800-borderSpacing-13,"F");
+        painter.drawText(borderSpacing+6,borderSpacing+30,"ROI");
         viewer->setPixmap(pic);
     });
     connect(EventCenter::Default(),&EventCenter::PatientSelected,[=](QObject* sender,QObject* data){