Function scaleImage

image_processing/resize_image.cpp:46–60

// ---- QImage API (avoids QPixmap round-trip in ContinuousPageWidget) ---------

QImage scaleImage(const QImage &image, int width, int height, ScaleMethod method)
{
    if ((image.width() == width && image.height() == height) || image.isNull())
        return image;

    switch (method) {
    case ScaleMethod::Nearest:
        return image.scaled(width, height, Qt::IgnoreAspectRatio, Qt::FastTransformation);
    case ScaleMethod::Bilinear:
        return image.scaled(width, height, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
    case ScaleMethod::Lanczos:
        return scaleImageLancir(image, width, height);
    }
    return image;
}