I would love to code simple image painting in HTML, CSS and probably jQuery also.

Let's say I have a original image, and I want make it colorized but only in part of hover (or 10x10px square or circle of image where cursor is).

I applied some filters to make it grayscale with CSS, but I have no idea how to colorize only hover part (not whole picture).

Example image of best result (keeping colorized advice would be great, but not necessarily).

I would love to code simple image painting in HTML, CSS and probably jQuery also.

Let's say I have a original image, and I want make it colorized but only in part of hover (or 10x10px square or circle of image where cursor is).

I applied some filters to make it grayscale with CSS, but I have no idea how to colorize only hover part (not whole picture).

Example image of best result (keeping colorized advice would be great, but not necessarily).

• javascript
• html
• css
• css-shapes

• 2 Please include the code you have tried keep it simple to reproduce the issue. – DaniP Commented Jan 9, 2015 at 16:03
• Stackexchange isn't really the best place to brainstorm ideas like this. It's more for troubleshooting what you've already attempted. Some issues I can identify for you: targeting where the cursor is, (.mousemove()) creating a mask for the colorized photo (background-clip), etc. – fontophilic Commented Jan 9, 2015 at 16:10
• 9 You could possibly use this - but alter it to fit your needs jsfiddle/4WP2C/19 – Chris Commented Jan 9, 2015 at 16:10

4 Answers 4

You could do this using svg's mask and filter.

CodePen

var img = document.getElementById('img');
img.addEventListener('mousemove', function(e) {
  document.getElementById('c').setAttribute('cx', e.clientX - img.getBoundingClientRect().left);
  document.getElementById('c').setAttribute('cy', e.clientY - img.getBoundingClientRect().top);
})

<svg id="img" width="600" height="300" viewBox="0 0 600 300">
  <defs>
    <filter id="f" filterUnits="userSpaceOnUse">
      <feColorMatrix type="saturate" values="0" />
    </filter>
    <mask id="m" maskUnits="userSpaceOnUse" x="0" y="0" width="600" height="300">
      <circle id="c" cx="-40" cy="-40" r="40" fill="white" />
    </mask>
  </defs>
  <image filter="url(#f)" width="600" height="300" xlink:href="http://www.lorempixel./600/300" />
  <image mask="url(#m)" width="600" height="300" xlink:href="http://www.lorempixel./600/300" />
</svg>

You could also get a smooth transition on the circle edges by using radialGradient.

CodePen

var img = document.getElementById('img');
img.addEventListener('mousemove', function(e) {
  var x = e.clientX - img.getBoundingClientRect().left;
  var y = e.clientY - img.getBoundingClientRect().top;
  document.getElementById('r').setAttribute('fx', x);
  document.getElementById('r').setAttribute('fy', y);
  document.getElementById('r').setAttribute('cx', x);
  document.getElementById('r').setAttribute('cy', y);
});

<svg id="img" width="600" height="300" viewBox="0 0 600 300">
  <defs>
    <radialGradient id="r" gradientUnits="userSpaceOnUse" cx="300" cy="150" r="400" fx="300" fy="150">
      <stop offset="0%" stop-color="white" />
      <stop offset="10%" stop-color="white" />
      <stop offset="12%" stop-color="black" />
      <stop offset="100%" stop-color="black" />
    </radialGradient>
    <filter id="f" filterUnits="userSpaceOnUse">
      <feColorMatrix type="saturate" values="0" />
    </filter>
    <mask id="m" maskUnits="userSpaceOnUse" x="0" y="0" width="600" height="300">
      <path d="M0,0 h600 v300 h-600z" fill="url(#r)" />
    </mask>
  </defs>
  <image filter="url(#f)" width="600" height="300" xlink:href="http://www.lorempixel./600/300" />
  <image mask="url(#m)" width="600" height="300" xlink:href="http://www.lorempixel./600/300" />
</svg>

I suggest avoiding CSS filters, as it is not supported in IE at all, and doesn't look like it is in the pipeline either.

I also would prefer to greyscale my images in photoshop, to have more control over the color balance and contrast. (But I'm a designer as well).

Instead, I'm going to layer a full color image over a grayscale image, fix the position of the colorful background image, and move the position of the top div with jQuery:

HTML

<div class="greykitty">
  <div class="colorfulkitty" style="top: 150px; left: 280px;">
  </div>
</div>

SCSS with normalize.css

body{
  background-color:whitesmoke;
}

div{
  height: 400px;
  width: 600px;
  background-repeat: no-repeat;
}


.greykitty{
  background-image: url("http://lorempixel./g/600/400/cats/10/");
}

.colorfulkitty{
    background-image: url("http://lorempixel./600/400/cats/10/");
  $circlesize: 150px;
  height:  $circlesize;
  width:  $circlesize;
  border-radius:   $circlesize;
  background-attachment: fixed;
  position: absolute;

}

JS with jQuery

$('.greykitty').mousemove(function (colorize) {
    var X = colorize.clientX;
    var Y = colorize.clientY;
    $('.colorfulkitty').css("top", (Y - 75) + 'px');
    $('.colorfulkitty').css("left", (X - 75) + 'px');
});

And my codepen: http://codepen.io/fontophilic/pen/XJpVje/

You can wrap you image in a HTML Element and add a div element element with box-shadow

$("figure").on('mousemove', function(e){
    $('.shadow').css({
       left: e.pageX - $(this).offset().left - 40,
       top: e.pageY - $(this).offset().top -40
    });
});

figure{
    position: relative;
    margin: 20px auto;
    width: 480px;
    height: 480px;
    overflow: hidden
}
figure:hover .shadow{
    opacity: 1
}
img{
    width: 100%
}

.shadow{
    position: absolute;
    left: 80px;
    top: 60px;
    z-index: 1;
    background: transparent;
    width: 100px;
    height: 100px;
    opacity: 0;
    transition: opacity .3s ease;
    border-radius: 50%;
    box-shadow: 0 0 0 60em rgba(0,0,0,.5)
}

<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<figure>
    <img src=http://i.imgur./orn8Dgf.jpg />
    <div  class=shadow></div>
</figure>

Base on this, i have solution for your problem:

• Use mark to overlay image

  <div class="container">`
      <div class="bg-image"></div>
      <div class="highlight-region"></div>
  </div>
  

• Grayscale on mark instead of image's container

   .container .bg-image { 
         opacity:0.3;
      -moz-filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale");
           -o-filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale");
           -webkit-filter: grayscale(100%);
           filter: gray;
           filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale");
      height:455px;
      width:606px;
  }
  

• set opacity = 0 on highlight-region

  .container div.highlight-region {
      height:150px; 
      width:150px;
      border-radius: 50%;
      opacity:0;
  }
  

Demo can see here: http://jsfiddle/MT4T7/438/