Converting JPG to PDF Issue

Aspose.PDF Product Family
1

Hi,

I’m using Aspose.PDF 24.1.0 to convert a JPG to a PDF file and have an issue where it loads/hangs forever.

Here is my sample code, using
Image2.jpg (651.4 KB)

// Set License
string licenseName = "Aspose.Total.NET.lic";
new License().SetLicense(licenseName);

// Test file paths
var jpgFilePath = @"C:\TestFiles\Image2.jpg";
var outputPath = @"C:\TestFiles\TestOutput.pdf";

using var document = new Document();

var documentsPages = document.Pages;
var newPage = documentsPages.Add();

var margin = 16.4; // This works fine if I use int 16 or 17 though
newPage.PageInfo.Margin = new MarginInfo(margin, margin, margin, margin);

using (var bitmap = new Bitmap(jpgFilePath))
{
    newPage.Paragraphs.Add(new Image
    {
        File = jpgFilePath,
        VerticalAlignment = VerticalAlignment.Center,
        HorizontalAlignment = HorizontalAlignment.Center,
        ImageScale = GetImageDownScale(bitmap, newPage)
    });
}

// This call hangs forever and valid pdf file is not created
document.Save(outputPath);

Console.WriteLine("Succesfully converted to pdf");

static double GetImageDownScale(System.Drawing.Image image, Page page)
{
    // If the image has a bigger dimension then the page, we need to scale it down.
    // https://forum.aspose.com/t/incorrect-aspect-ratio-when-adding-large-images-to-pdf/227538/2
    // The way to calculate the image scale is to compare the vertical and horizontal scales to find the smaller one.
    // The vertical scale is the "usable page width" (e.g. page with less horizontal margins) divided by the image width.
    // The horizontal scale is the "usable page height" (e.g. page height less vertical margins) divided by the image height.
    var pageInfo = page.PageInfo;
    var pageMargin = pageInfo.Margin;
    var minimumScale = Math.Min(
        (pageInfo.Width - pageMargin.Left - pageMargin.Right) / image.Width,
        (pageInfo.Height - pageMargin.Top - pageMargin.Bottom) / image.Height);

    // If the minimum scale is larger than 1, that means the image is smaller than the page, there's no need to scale down.
    return Math.Min(minimumScale, 1);
}

The code is adding margin to the page, and then scaling the image to fit inside that margin.

The issue happens when I set the PageInfo.Margin to a decimal value, eg 16.4. The call to Document.Save(outputPath) just hangs forever and the pdf document is not created.

Is there a reason that this code hangs forever and does not convert the image to a pdf?

Thanks,
Will

2

@bvadala

It looks like the image is not being scaled respectively to the available space on the page due to Math.Min() usage.

var minimumScale = Math.Min(
    (pageInfo.Width - pageMargin.Left - pageMargin.Right) / image.Width,
    (pageInfo.Height - pageMargin.Top - pageMargin.Bottom) / image.Height);

The above line of code is scaling the image at minimum value which may be exceeding the available room on PDF page considering margins. When we replaced Math.Min() with Math.Max(), output got generated successfully.
TestOutput.pdf (1.0 MB)

Please note that above comments are just speculations against the initial investigation performed in our environment. Please feel free to comment or share if you have further concerns.