title: How to fix poor interpolation of very small rasters in viewed pdfs (evince and chrome)
body: <p>I want to create a visualization of a matrix for some academic work. I decided to go about this by having the pixels in the image correspond to the values in the matrix. I created the nice small png that follows:</p>
  
  <p><img src="https://i.stack.imgur.com/QB03a.png" alt="enter image description here"></p>
  
  <p>When properly scaled up, you get a very reasonable image:</p>
  
  <p><img src="https://i.stack.imgur.com/bB69Z.png" alt="enter image description here"></p>
  
  <p>This is a screenshot from within inkscape. However, when export this as a pdf, both evince and chrome do a terrible job at upscaling what should be very trivial, and instead I get something that looks like:</p>
  
  <p><img src="https://i.stack.imgur.com/g2TBp.png" alt="enter image description here"></p>
  
  <p>The pdf itself seems to scale appropriately well for printing, but unfortunately I do a lot of my editing without printing, and this looks unacceptable. I did find <a href="https://groups.google.com/forum/#!topic/prawn-ruby/MbMsCx862iY" rel="nofollow noreferrer">this incredibly old thread</a> about people seeming to have a similar issue with chrome's pdf viewer, and the "solution" was to just upscale the raster graphics. This is a solution, but is terribly inefficient.</p>
  
  <p>Is anyone aware of a way to change the pdf so that it gets upscaled appropriately? Maybe a config change in evince or chrome that will render these properly? Even a nice way to go from a raster image to a vector image might be suitable?</p>