Oscar Sun

                  using Microsoft.Office.Interop.Word;//https://social.msdn.microsoft.com/Forums/office/en-US/c6a73b86-d388-4733-8e5b-d00742b40dd7/turn-off-picture-compression-in-interop?forum=worddev

// ...

string imagePath = @"c:\temp\win10.jpg";

Application wordApp = new Application();
Document wordDoc = wordApp.Documents.Add();

// Create an InlineShape in the InlineShapes collection where the picture should be added later
// It is used to get automatically scaled sizes.
InlineShape autoScaledInlineShape = wordDoc.InlineShapes.AddPicture(imagePath);
float scaledWidth = autoScaledInlineShape.Width;
float scaledHeight = autoScaledInlineShape.Height;

// Create a new Shape and fill it with the picture
Shape newShape = wordDoc.Shapes.AddShape(1, 0, 0, scaledWidth, scaledHeight);
newShape.Fill.UserPicture(imagePath);

// Convert the Shape to an InlineShape and optional disable Border
InlineShape finalInlineShape = newShape.ConvertToInlineShape();
finalInlineShape.Line.Visible = Microsoft.Office.Core.MsoTriState.msoFalse;

// Cut the range of the InlineShape to clipboard
autoScaledInlineShape.Delete();
finalInlineShape.Range.Cut();

// optional create new Range
Range docRange = wordDoc.Range();

// And paste it to the target Range
docRange.Paste();

wordDoc.SaveAs2(@"c:\temp\test.docx");
wordDoc.Close();
wordApp.Quit();