Inconsisten RasterImage Resolution between Windows and Linux

Aspose.Imaging Product Family
1

RasterImage.HorizontalResolution and RasterImage.VerticalResolution has different values on Windows and Linux. You can check it using following code and image attached, on Windows both resolutions equal 96, but on Linux its 198.12. It occurs on Aspose.Imaging 25.3.0

using System.Runtime.InteropServices;
using Aspose.Imaging;
using Image = Aspose.Imaging.Image;

var filename = Path.GetFullPath(@"./NoDpi1.jpg");

Console.WriteLine(RuntimeInformation.OSDescription);

var source = (RasterImage)Image.Load(filename);

Console.WriteLine("SOURCE HORIZONTAL - " + source.HorizontalResolution);
Console.WriteLine("SOURCE VERTICAL - " + source.VerticalResolution);

NoDpi1.jpg (464.6 KB)

There is also another image using which we can reproduse this behaviour, but unfortunately iam unable to provide it for testing. But its also a jpeg and its Raster Image on older versions of Aspose.Imaging used to show resolution of 1, but after update its 96 on Windows and 72 on Linux.

3

Hello, @directum
This is not a bug. It is an expectable behavior. When jpeg does not contain resolution info, JpegImage returns the default DPI for a current OS (Windows 96, others 72).
Other viewers show the same resolution information in such a case.
If you wish to know if JPEG image has or does not have resolution info you could get and analyze jfifData

JFIFData jfifData = jpegImage.getJfif();