Resizing Large Images to Fit in the PDF Page
Environment
| Version | Product | Author |
|---|---|---|
| 2024.2.426 | RadPdfProcessing | Desislava Yordanova |
Description
When inserting an image to a PDF file using RadPdfProcessing, the resulting PDF may cut off parts of the image if its dimensions exceed the PDF page size. The goal is to:
- Display the image as is if it fits on the page without resizing.
- If the image is too large, shrink it to fit on the page while preserving the aspect ratio.
This KB article also answers the following questions:
- How do I convert an image to a PDF while fitting it on the page in RadPdfProcessing?
- How can I preserve the aspect ratio of an image when converting it to PDF?
- What is the method to resize images for PDF conversion in RadPdfProcessing?
Solution
To resize a large image to fit within the PDF page dimensions while preserving its aspect ratio, follow these steps:
-
Determine the dimensions of the image by creating an [ImageSource(slug://radpdfprocessing-model-imagesource) instance from the image file.
-
Check if the image dimensions exceed the page size. If they do, calculate the new size of the image that preserves the aspect ratio and fits within the page.
-
Use the
DrawImage(ImageSource source, Size size)method to draw the resized image on the PDF page. -
To preserve the aspect ratio, use the following code snippet that automatically adjusts the image size based on the page dimensions:
Telerik.Documents.ImageUtils.ImagePropertiesResolver defaultImagePropertiesResolver = new Telerik.Documents.ImageUtils.ImagePropertiesResolver();
Telerik.Windows.Documents.Extensibility.FixedExtensibilityManager.ImagePropertiesResolver = defaultImagePropertiesResolver;
string[] imageFiles = Directory.GetFiles(@"..\..\..\MyImages");
foreach (string imageFilePath in imageFiles)
{
RadFixedDocument document = new RadFixedDocument();
RadFixedPage fixedPage = document.Pages.AddPage();
Telerik.Documents.Primitives.Size pageSize = new Telerik.Documents.Primitives.Size(
Telerik.Windows.Documents.Media.Unit.MmToDip(210),
Telerik.Windows.Documents.Media.Unit.MmToDip(297));
Telerik.Documents.Primitives.Size original;
using (Bitmap bmp = new Bitmap(imageFilePath))
{
original = new Telerik.Documents.Primitives.Size(bmp.Width, bmp.Height);
}
double maxSize = Math.Min(pageSize.Width, pageSize.Height);
float percent = (new List<float> { (float)maxSize / (float)original.Width, (float)maxSize / (float)original.Height }).Min();
Telerik.Documents.Primitives.Size resultSize = new Telerik.Documents.Primitives.Size((int)Math.Floor(original.Width * percent), (int)Math.Floor(original.Height * percent));
if (resultSize.Width > resultSize.Height)
{
pageSize = new Telerik.Documents.Primitives.Size(
Telerik.Windows.Documents.Media.Unit.MmToDip(297),
Telerik.Windows.Documents.Media.Unit.MmToDip(210));
}
fixedPage.Size = pageSize;
Telerik.Windows.Documents.Fixed.Model.Objects.Image image = new Telerik.Windows.Documents.Fixed.Model.Objects.Image();
FileStream fileStream = new FileStream(imageFilePath, FileMode.Open);
ImageSource imageSrc = new ImageSource(fileStream);
image.ImageSource = imageSrc;
image.Width = resultSize.Width;
image.Height = resultSize.Height;
SimplePosition simplePosition = new SimplePosition();
simplePosition.Translate(5, 5);
image.Position = simplePosition;
fixedPage.Content.Add(image);
PdfFormatProvider provider = new PdfFormatProvider();
string outputFilePath = "output" + Guid.NewGuid().ToString() + ".pdf";
using (Stream output = File.OpenWrite(outputFilePath))
{
provider.Export(document, output);
}
Process.Start(new ProcessStartInfo() { FileName = outputFilePath, UseShellExecute = true });
}This approach ensures that images are resized to fit within the PDF page dimensions without losing their aspect ratio.
| Vertical Image | Horizontal Image |
|---|---|
 |  |