dynamically adjusts the imageSize so that each module is an integer number of pixels, avoiding possible aliasing artifacts when size isn’t divisible evenly by qrSize + 2 × border.

src/QrCodeGenerator.cpp

@@ -126,10 +126,9 @@ QString QrCodeGenerator::toSvgString(const qrcodegen::QrCode &qr,
 //   return image;
 // }
 
-
-// QR code image is being rendered from SVG output, not directly from bitmaps or matrices
-// QSvgRenderer has internal limits on path complexity or buffer size — hitting
-// those leads to the truncation warning.
+// QR code image is being rendered from SVG output, not directly from bitmaps or
+// matrices QSvgRenderer has internal limits on path complexity or buffer size —
+// hitting those leads to the truncation warning.
 //  If the generated SVG string is too large or malformed, the QSvgRenderer will
 //  throw warnings.
 // like:  W : qt.svg: Invalid path data; path truncated.
@@ -137,23 +136,28 @@ QImage QrCodeGenerator::qrCodeToImage(const qrcodegen::QrCode &qrCode,
                                       quint16 border, quint16 size) const
 {
   const int qrSize = qrCode.getSize();
-  const int scale = size / (qrSize + 2 * border);
-
-  QImage image(size, size, QImage::Format_RGB32);
+  const int totalSize = qrSize + 2 * border;
+  // Calculate scaling factor to fit requested size
+  const int pixelSize = size / totalSize;
+  const int imageSize = pixelSize * totalSize;
+  // Create the output image
+  QImage image(imageSize, imageSize, QImage::Format_RGB32);
   image.fill(Qt::white);
 
   QPainter painter(&image);
   painter.setBrush(Qt::black);
   painter.setPen(Qt::NoPen);
 
+  // Draw each QR module (black square)
   for (int y = 0; y < qrSize; ++y)
   {
     for (int x = 0; x < qrSize; ++x)
     {
       if (qrCode.getModule(x, y))
       {
-        QRect rect((x + border) * scale, (y + border) * scale, scale, scale);
-        painter.drawRect(rect);
+        int xPos = (x + border) * pixelSize;
+        int yPos = (y + border) * pixelSize;
+        painter.drawRect(xPos, yPos, pixelSize, pixelSize);
       }
     }
   }