CSS

css image sharpen

img {
  image-rendering: auto;
  image-rendering: crisp-edges;
  image-rendering: pixelated;
}

css image sharpen

img {
  image-rendering: pixelated;
}

css image sharpen

 filter: none; 
-webkit-filter: blur(0px); 
-moz-filter: blur(0px); 
-ms-filter: blur(0px);
filter:progid:DXImageTransform.Microsoft.Blur(PixelRadius='0');

css image sharpen

<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAQAAAAECAYAAACp8Z5+AAAAAXNSR0IArs4c6QAAACdJREFUCB1j9Pf3/88ABMmMjCCKgQlMIhGMu3btAquY9mMDWBhDBQAutwfDrUlKzQAAAABJRU5ErkJggg==" />