My images look awful in the final pdf. If I keep increasing the dpi, this doesn't help, and sometimes makes the image look worse. I understand that if I had a vectorized image it would solve my problem, but using Inkscape and outputting a *.png file is simple and guaranteed to work. The image below shows how the same file rendered in an image viewer vs. the pdf are very different. Notice how the red line disappears in the center.
Image resolution for this example was 440dpi.
Is there a package or option I should be using to get a better output? Is this the fault of the pdf viewer?