Does anyone know why this image is so blurry?

I did a convert from pdf to png and it turned out like that. Before deleting imagemagick and it's entire toolset from software-center most of my image programs were displaying like this image. Now for the most part it's just blurry, though a couple still display like that such as gimp. I am running in xfce maybe it's to do with the distribution enviornment. Main issue is the absurd blurriness. I reinstalled all additional packages that were available for imagemagick in the software-center

I use convert *.pdf *.png & mogrify -format png *.pdf to convert

Now on the other hand if I converted the file to djvu and converted that to a tif. The images have no problem converting. More so it does not generate an oversized tif file of around 25mb compared to 3mb with djvu which is super clear & no blurriness.