/// <summary>
/// Gets the background image for the page
/// </summary>
/// <returns></returns>
internal System.Drawing.Bitmap GetBackgroundImage(int subsample, bool resizeImage = false)
{
Verify.SubsampleRange(subsample);
int width = _Page.Width;
int height = _Page.Height;
BG44Chunk[] backgrounds = _Page.PageForm?.GetChildrenItems <BG44Chunk>();
if ((backgrounds == null || backgrounds.Length == 0) && width > 0 && height > 0)
{
return(DjvuImage.CreateBlankImage(Brushes.White, width, height));
}
// Get the composite background image
Wavelet.IInterWavePixelMap backgroundMap = null;
lock (LoadingLock)
{
foreach (BG44Chunk background in backgrounds)
{
if (backgroundMap == null)
{
// Get the initial image
backgroundMap = background.BackgroundImage;
}
else
{
if (!IsBackgroundDecoded)
{
background.ProgressiveDecodeBackground(backgroundMap);
}
}
}
IsBackgroundDecoded = true;
}
Bitmap result = backgroundMap.GetPixelMap().ToImage();
if (resizeImage)
{
int newWidth = width / subsample;
int newHeight = height / subsample;
return(DjvuImage.ResizeImage(result, newWidth, newHeight));
}
else
{
return(result);
}
}
internal DjvuNet.Graphics.Map GetBackgroundMap(bool rebuild = false)
{
if (!rebuild && IsBackgroundDecoded)
{
return(_Page.PageForm?.GetChildrenItems <BG44Chunk>().FirstOrDefault()?.BackgroundImage.GetPixelMap() ?? null);
}
else if (rebuild && IsBackgroundDecoded)
{
IsBackgroundDecoded = false;
}
int width = _Page.Width;
int height = _Page.Height;
BG44Chunk[] backgrounds = _Page.PageForm?.GetChildrenItems <BG44Chunk>();
if ((backgrounds == null || backgrounds.Length == 0) && width > 0 && height > 0)
{
return(new Graphics.PixelMap(new sbyte[width * height], width, height));
}
// Get the composite background image
Wavelet.IInterWavePixelMap backgroundMap = null;
lock (LoadingLock)
{
foreach (BG44Chunk background in backgrounds)
{
if (backgroundMap == null)
{
// Get the initial image
backgroundMap = background.BackgroundImage;
}
else
{
if (!IsBackgroundDecoded)
{
background.ProgressiveDecodeBackground(backgroundMap);
}
}
}
IsBackgroundDecoded = true;
}
return(backgroundMap.GetPixelMap());
}
