Pixelated image when printing with larger scales

[Siberian]

I need to place an image in a view. The view has a scale of 1:200, but with this scale the image becomes heavily pixelated in the PDF. It becomes less so with smaller scales, but that's not really an option if I'm to fit the view on any normal sheet size. Scaling up the image itself also works with the pixels, but that doesn't solve the issue since I need to make it a size that fits the surrounding graphics. I've tried increasing the PDF resolution, printing both vector and raster, but none of these affect the result in any major way. Any ideas on this?

[SLW210]

The only way I know is to use an image editor to sharpen up the image or to make a vector image if possible (Photoshop/Illustrator or GIMP/Inkscape). You might also see if the same image can be had with a higher initial resolution.