Maintain original image size when moving images in open xml

When inserting images into content control boxes using openxml, the image dimensions will not change to those of the image, you will need to manually do this.

Which objects?

There are two places where the image size needs to be set, inside the DocumentFormat.OpenXml.Drawing.Pictures.Picture object and the DocumentFormat.OpenXml.Drawing.Wordprocessing.Inline object. Both of these objects contain an DocumentFormat.OpenXml.Drawing.Wordprocessing.Extent object which contains the Cx and Cy values for the image.

What size?

Now the next problem is knowing what the Cx and Cy values should be set to. Use the System.Drawing.Image object to get the Width and Height properties from your image. However, word image dimensions are not stored in pixels, they are stored in points.

Converting pixels to points can be very complicated when you're working with text but luckily with images there is a constant value we can use to calculate the points from a pixel value, which is 9525.

Code example please?