public string GetImages(Params par)
{
string path = System.Web.HttpContext.Current.Server.MapPath(par.path);
List <AnnotationJSON> res = new List <AnnotationJSON>();
GdPicturePDF pdf = new GdPicturePDF();
AnnotationManager an = new AnnotationManager();
GdPictureImaging im = new GdPictureImaging();
int width = 0;
int height = 0;
int left = 0;
int top = 0;
pdf.SetOrigin(PdfOrigin.PdfOriginTopLeft);
pdf.SetMeasurementUnit(PdfMeasurementUnit.PdfMeasurementUnitInch);
//this API is only works for PDF files , if you need to process image based files you could implement similar logic using GdPictureImaging
//instead of GdPicturePDF
pdf.LoadFromFile(path, false);
an.InitFromGdPicturePDF(pdf);
for (int i = 1; i <= pdf.GetPageCount(); i++)
{
an.SelectPage(i);
int count = an.GetAnnotationCount();
if (count > 0)
{
List <Annotation> ans = new List <Annotation>();
for (int m = 0; m < count; m++)
{
Annotation annot = an.GetAnnotationFromIdx(m);
annot.Rotation = 0;
ans.Add(annot);
}
an.BurnAnnotationsToPage(false);
//we render PDF page to an image to crop
int imageNr = pdf.RenderPageToGdPictureImage(300, false);
for (int y = 0; y < count; y++)
{
//we copy the same image so we can crop it and send back
int imageCrop = im.CreateClonedGdPictureImage(imageNr);
Annotation annot = ans[y];
//conversion from inches to pixels
left = (int)Math.Ceiling(annot.Left * 300 + 0.5);
top = (int)Math.Ceiling(annot.Top * 300 + 0.5);
width = (int)Math.Ceiling(annot.Width * 300 + 0.5);
height = (int)Math.Ceiling(annot.Height * 300 + 0.5);
//cropping the immage to get snapshot of the annotation
im.Crop(imageCrop, left - width / 2, top - height / 2, width, height);
//rescale the image to 20%
im.Scale(imageCrop, 20, System.Drawing.Drawing2D.InterpolationMode.High);
//prepare image and send it as base64
byte[] arr = { };
int length = 0;
im.SaveAsByteArray(imageCrop, ref arr, ref length, GdPicture14.DocumentFormat.DocumentFormatJPEG, 100);
string bs = System.Convert.ToBase64String(arr);
AnnotationJSON json = new AnnotationJSON();
json.Image = bs;
res.Add(json);
//releasing the resources
im.ReleaseGdPictureImage(imageCrop);
}
im.ReleaseGdPictureImage(imageNr);
}
}
pdf.Dispose();
return(JsonConvert.SerializeObject(res));
}