svgsharpness

<svg width="0" height="0" style="position:absolute;left:-9999px" aria-hidden="true">
  <defs>
    <filter id="richSharpenBright" filterUnits="objectBoundingBox" x="-10%" y="-10%" width="120%" height="120%">
      <feConvolveMatrix in="SourceGraphic" order="3"
        kernelMatrix="0 -1 0 -1 5 -1 0 -1 0"
        divisor="1" bias="0" edgeMode="duplicate" result="sharpened" />
      <feColorMatrix in="sharpened" type="matrix" result="colorBoost"
        values="
          1.12 0    0    0   0
          0    1.08 0    0   0
          0    0    1.04 0   0
          0    0    0    1   0" />
      <feColorMatrix in="colorBoost" type="matrix" result="tinted"
        values="
          1 0 0 0 0.02
          0 1 0 0 0.01
          0 0 1 0 0
          0 0 0 1 0" />
      <feComponentTransfer in="tinted" result="brightCopy">
        <feFuncR type="linear" slope="1.08" intercept="0.02"/>
        <feFuncG type="linear" slope="1.08" intercept="0.02"/>
        <feFuncB type="linear" slope="1.08" intercept="0.02"/>
      </feComponentTransfer>
      <feBlend in="tinted" in2="brightCopy" mode="screen" result="screened"/>
      <feComponentTransfer in="screened">
        <feFuncR type="gamma" amplitude="1" exponent="1" offset="0"/>
        <feFuncG type="gamma" amplitude="1" exponent="1" offset="0"/>
        <feFuncB type="gamma" amplitude="1" exponent="1" offset="0"/>
      </feComponentTransfer>
    </filter>
  </defs>
</svg>