public static IEnumerable <Bitmap> GetBitmapPagesEnum(string path, float zoom = 1.0f)
{
IntPtr ctx = NativeMethods.NewContext(); // Creates the context
IntPtr stm = NativeMethods.OpenFile(ctx, path); // opens file test.pdf as a stream
IntPtr doc = NativeMethods.OpenDocumentStream(ctx, stm); // opens the document
int pn = NativeMethods.CountPages(doc); // gets the number of pages in the document
for (int i = 0; i < pn; i++) // iterate through each pages
{
IntPtr p = NativeMethods.LoadPage(doc, i); // loads the page (first page number is 0)
RectangleMu b = new RectangleMu();
NativeMethods.BoundPage(doc, p, ref b); // gets the page size
var page = RenderPage(ctx, doc, p, b, zoom, zoom);
NativeMethods.FreePage(doc, p); // releases the resources consumed by the page
yield return(page);
}
NativeMethods.CloseDocument(doc); // releases the resources
NativeMethods.CloseStream(stm);
NativeMethods.FreeContext(ctx);
}
/// <summary>
/// Get the page with the specified page number (1 indexed).
/// </summary>
/// <param name="pageNumber">The number of the page to return, this starts from 1.</param>
/// <returns></returns>
public Bitmap GetPage(int pageNumber, float zoom = 1.0f)
{
if (pageNumber <= 0 || pageNumber > PagesCount)
{
throw new ArgumentOutOfRangeException("pageNumber");
}
if (zoom <= 0)
{
throw new ArgumentException("PdfImageConverter(): zoom must be positive and bigger than 0.");
}
IntPtr p = NativeMethods.LoadPage(_doc, pageNumber - 1); // loads the page (first page number is 0)
RectangleMu b = new RectangleMu();
NativeMethods.BoundPage(_doc, p, ref b); // gets the page size
var page = RenderPage(_ctx, _doc, p, b, zoom, zoom);
NativeMethods.FreePage(_doc, p); // releases the resources consumed by the page
return(page);
}
internal RectangleMu Transform(RectangleMu rect)
{
Point s, t, u, v;
if (rect.IsInfinite)
{
return(rect);
}
s.X = rect.Left; s.Y = rect.Top;
t.X = rect.Left; t.Y = rect.Bottom;
u.X = rect.Right; u.Y = rect.Bottom;
v.X = rect.Right; v.Y = rect.Top;
s = this.Transform(s);
t = this.Transform(t);
u = this.Transform(u);
v = this.Transform(v);
rect.Left = Min4(s.X, t.X, u.X, v.X);
rect.Top = Min4(s.Y, t.Y, u.Y, v.Y);
rect.Right = Max4(s.X, t.X, u.X, v.X);
rect.Bottom = Max4(s.Y, t.Y, u.Y, v.Y);
return(rect);
}
public static int GetBitmapHeight(RectangleMu pageBound, float zoomY = 1.0f)
{
return((int)(zoomY * (pageBound.Bottom - pageBound.Top)));
}
public static extern void BoundPage(IntPtr doc, IntPtr page, ref RectangleMu bound);
private static Bitmap RenderPage(IntPtr context, IntPtr document, IntPtr page, RectangleMu pageBound, float zoomX = 1.0f, float zoomY = 1.0f)
{
MatrixMu ctm = new MatrixMu();
IntPtr pix = IntPtr.Zero;
IntPtr dev = IntPtr.Zero;
// gets the size of the scaled page
int width = GetBitmapWidth(pageBound, zoomX); // (int)(zoomX * (pageBound.Right - pageBound.Left));
int height = GetBitmapHeight(pageBound, zoomY); // (int)(zoomY * (pageBound.Bottom - pageBound.Top));
ctm.A = zoomX;
ctm.D = zoomY; // sets the matrix as (zoomX,0,0,zoomY,0,0)
// creates a pixmap the same size as the width and height of the page
pix = NativeMethods.NewPixmap(context, NativeMethods.LookupDeviceColorSpace(context, "DeviceRGB"), width, height);
// sets white color as the background color of the pixmap
NativeMethods.ClearPixmap(context, pix, 0xFF);
// creates a drawing device
dev = NativeMethods.NewDrawDevice(context, pix);
// draws the page on the device created from the pixmap
NativeMethods.RunPage(document, page, dev, ref ctm, IntPtr.Zero);
NativeMethods.FreeDevice(dev); // frees the resources consumed by the device
dev = IntPtr.Zero;
// creates a colorful bitmap of the same size of the pixmap
Bitmap bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);
//bmp.SetResolution(300, 300);
var imageData = bmp.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadWrite, bmp.PixelFormat);
unsafe
{ // converts the pixmap data to Bitmap data
// gets the rendered data from the pixmap
byte *ptrSrc = (byte *)NativeMethods.GetSamples(context, pix);
byte *ptrDest = (byte *)imageData.Scan0;
for (int y = 0; y < height; y++)
{
byte *pl = ptrDest;
byte *sl = ptrSrc;
for (int x = 0; x < width; x++)
{
//Swap these here instead of in MuPDF because most pdf images will be rgb or cmyk.
//Since we are going through the pixels one by one
//anyway swap here to save a conversion from rgb to bgr.
pl[2] = sl[0]; //b-r
pl[1] = sl[1]; //g-g
pl[0] = sl[2]; //r-b
//sl[3] is the alpha channel, we will skip it here
pl += 3;
sl += 4;
}
ptrDest += imageData.Stride;
ptrSrc += width * 4;
}
}
// free bitmap in memory
bmp.UnlockBits(imageData);
NativeMethods.DropPixmap(context, pix);
return(bmp);
}
public static int GetBitmapWidth(RectangleMu pageBound, float zoomX = 1.0f)
{
return((int)(zoomX * (pageBound.Right - pageBound.Left)));
}
