画像を和色のみにした場合に
どんな見た目になるかどうかを
軽くチェックするための html を
作成しましたので
皆さんの役に立てばと思い
公開してみようと思います。

オンラインで動作するバージョンはこちら

ダウンロードはこちら(BOOTH)
ダウンロードはこちら(Google Drive)

洋色バージョンのダウンロードはこちら
 セーフカラーバージョンのダウンロードはこちら

このアプリケーションの見た目

この html の説明

画像を和色のみにした場合に
どんな見た目になるかどうかを
軽くチェックする html です。

画像ファイルを選択すると
左右にその画像が展開されます。
そして右側の画像が和色に変換されていきます。

境界線が乱れるため
この html で変換した物を
完成品にするのは難しいですが
画像を修正する際の指標にする事ができます。

このサイトに載っているいずれかの色に変換します。

この html ファイルのコード

この html ファイルは
下記のコードで動いています。

html ファイルを新規作成して
中身をこの内容にしても動作します。

使用したコード

<html lang="ja">
<head>
    <title>画像を和色のみの構成にするサイト | Gifted Style</title>
    <meta name="description" content="画像を和色のみの構成にするサイトです。"/>
    <style>
.progress {
  border-radius: 30px;
  height: 40px;
  background: #ddd;
  overflow: hidden;
}
.bar {
  background: #FFC100;
  border-radius: inherit;
  height: 100%;
  width: 0%;
  transition: 2s;
}
    </style>
</head>
<body>
<img src="" id="preview">
<canvas id="canvas"></canvas>
<canvas id="canvas2"></canvas></br>
<input type="file" accept="image/*" id="getfile"></br>
<div class="progress">
  <div class="bar" id="Bar"></div>
</div></br></br>
このサイトは画像を和色のみにした場合に</br>
どんな見た目になるかどうかを軽くチェックするサイトです。</br></br>
画像ファイルを選択すると</br>
左右にその画像が展開されます。</br>
そして右側の画像が和色に変換されていきます。</br></br>
境界線が乱れるため</br>
このサイトで変換した物を</br>
完成品にするのは難しいですが</br>
画像を修正する際の指標にする事ができます。</br></br>
<a href="https://www.colordic.org/w" target="_blank">このサイト</a> に載っているいずれかの色に変換します。</br></br>
3 番目に出現する画像は</br>
2 番目の画像のノイズ削除処理をしたものです。</br>
5 × 5 のメディアンフィルタです。</br></br>
<script>
function MyThread(i, ctx, canvas) {
for(let j = 0; j < canvas.height; j++) {
          const imageData = ctx.getImageData(i, j, 1, 1);
          let r = imageData.data[0];
          let g = imageData.data[1];
          let b = imageData.data[2];
          let a = imageData.data[3];
          let array = ["#fef4f4" ,"#96514d" ,"#e6b422" ,"#006e54" ,"#895b8a" ,"#fdeff2" ,"#8d6449" ,"#d9a62e" ,"#00a381" ,"#824880" ,"#e9dfe5" ,"#deb068" ,"#d3a243" ,"#38b48b" ,"#915c8b" ,"#e4d2d8" ,"#bf794e" ,"#c89932" ,"#00a497" ,"#9d5b8b" ,"#f6bfbc" ,"#bc763c" ,"#d0af4c" ,"#80aba9" ,"#7a4171" ,"#f5b1aa" ,"#b98c46" ,"#8b968d" ,"#5c9291" ,"#bc64a4" ,"#f5b199" ,"#b79b5b" ,"#6e7955" ,"#478384" ,"#b44c97" ,"#efab93" ,"#b77b57" ,"#767c6b" ,"#43676b" ,"#aa4c8f" ,"#f2a0a1" ,"#b68d4c" ,"#888e7e" ,"#80989b" ,"#cc7eb1" ,"#f0908d" ,"#ad7d4c" ,"#5a544b" ,"#2c4f54" ,"#cca6bf" ,"#ee827c" ,"#ad7d4c" ,"#56564b" ,"#1f3134" ,"#c4a3bf" ,"#f09199" ,"#ae7c4f" ,"#555647" ,"#47585c" ,"#e7e7eb" ,"#f4b3c2" ,"#ad7e4e" ,"#494a41" ,"#485859" ,"#dcd6d9" ,"#eebbcb" ,"#ae7c58" ,"#6b6f59" ,"#6c848d" ,"#d3cfd9" ,"#e8d3c7" ,"#a86f4c" ,"#474b42" ,"#53727d" ,"#d3ccd6" ,"#e8d3d1" ,"#946243" ,"#333631" ,"#5b7e91" ,"#c8c2c6" ,"#e6cde3" ,"#917347" ,"#5b6356" ,"#426579" ,"#a6a5c4" ,"#e5abbe" ,"#956f29" ,"#726250" ,"#4c6473" ,"#a69abd" ,"#e597b2" ,"#8c7042" ,"#9d896c" ,"#455765" ,"#a89dac" ,"#e198b4" ,"#7b6c3e" ,"#94846a" ,"#44617b" ,"#9790a4" ,"#e4ab9b" ,"#d8a373" ,"#897858" ,"#393f4c" ,"#9e8b8e" ,"#e09e87" ,"#cd8c5c" ,"#716246" ,"#393e4f" ,"#95859c" ,"#d69090" ,"#cd5e3c" ,"#cbb994" ,"#203744" ,"#95949a" ,"#d4acad" ,"#cb8347" ,"#d6c6af" ,"#4d4c61" ,"#71686c" ,"#c97586" ,"#c37854" ,"#bfa46f" ,"#eaf4fc" ,"#705b67" ,"#c099a0" ,"#c38743" ,"#9e9478" ,"#eaedf7" ,"#634950" ,"#b88884" ,"#c39143" ,"#a59564" ,"#e8ecef" ,"#5f414b" ,"#b48a76" ,"#bf783a" ,"#715c1f" ,"#ebf6f7" ,"#4f455c" ,"#a86965" ,"#bb5535" ,"#c7b370" ,"#c1e4e9" ,"#5a5359" ,"#a25768" ,"#bb5520" ,"#dcd3b2" ,"#bce2e8" ,"#594255" ,"#ec6d71" ,"#b55233" ,"#a19361" ,"#a2d7dd" ,"#524748" ,"#eb6ea5" ,"#aa4f37" ,"#8f8667" ,"#abced8" ,"#513743" ,"#e95295" ,"#9f563a" ,"#887938" ,"#a0d8ef" ,"#e6eae3" ,"#e7609e" ,"#9f563a" ,"#6a5d21" ,"#89c3eb" ,"#d4dcd6" ,"#d0576b" ,"#9a493f" ,"#918754" ,"#84a2d4" ,"#d4dcda" ,"#c85179" ,"#98623c" ,"#a69425" ,"#83ccd2" ,"#d3cbc6" ,"#e9546b" ,"#965042" ,"#ada250" ,"#84b9cb" ,"#c8c2be" ,"#e95464" ,"#965036" ,"#938b4b" ,"#698aab" ,"#b3ada0" ,"#c85554" ,"#95483f" ,"#8c8861" ,"#008899" ,"#a99e93" ,"#c53d43" ,"#954e2a" ,"#a1a46d" ,"#00a3af" ,"#a58f86" ,"#e83929" ,"#8f2e14" ,"#726d40" ,"#2a83a2" ,"#928178" ,"#e60033" ,"#8a3319" ,"#928c36" ,"#59b9c6" ,"#887f7a" ,"#e2041b" ,"#8a3b00" ,"#dccb18" ,"#2ca9e1" ,"#b4866b" ,"#d7003a" ,"#852e19" ,"#d7cf3a" ,"#38a1db" ,"#b28c6e" ,"#c9171e" ,"#7b4741" ,"#c5c56a" ,"#0095d9" ,"#a16d5d" ,"#d3381c" ,"#773c30" ,"#c3d825" ,"#0094c8" ,"#9f6f55" ,"#ce5242" ,"#783c1d" ,"#b8d200" ,"#2792c3" ,"#8c6450" ,"#d9333f" ,"#762f07" ,"#e0ebaf" ,"#007bbb" ,"#856859" ,"#b94047" ,"#752100" ,"#d8e698" ,"#5383c3" ,"#765c47" ,"#ba2636" ,"#6c3524" ,"#c7dc68" ,"#5a79ba" ,"#6f514c" ,"#b7282e" ,"#683f36" ,"#99ab4e" ,"#4c6cb3" ,"#6f4b3e" ,"#a73836" ,"#664032" ,"#7b8d42" ,"#3e62ad" ,"#544a47" ,"#9e3d3f" ,"#6d3c32" ,"#69821b" ,"#1e50a2" ,"#543f32" ,"#a22041" ,"#583822" ,"#aacf53" ,"#507ea4" ,"#554738" ,"#a22041" ,"#6c2c2f" ,"#b0ca71" ,"#19448e" ,"#433d3c" ,"#f8f4e6" ,"#640125" ,"#b9d08b" ,"#164a84" ,"#432f2f" ,"#ede4cd" ,"#f8b862" ,"#839b5c" ,"#165e83" ,"#3f312b" ,"#e9e4d4" ,"#f6ad49" ,"#cee4ae" ,"#274a78" ,"#302833" ,"#ebe1a9" ,"#f39800" ,"#82ae46" ,"#2a4073" ,"#ffffff" ,"#f2f2b0" ,"#f08300" ,"#a8c97f" ,"#223a70" ,"#fffffc" ,"#e4dc8a" ,"#ec6d51" ,"#9ba88d" ,"#192f60" ,"#f7fcfe" ,"#f8e58c" ,"#ee7948" ,"#c8d5bb" ,"#1c305c" ,"#f8fbf8" ,"#ddbb99" ,"#ed6d3d" ,"#c1d8ac" ,"#0f2350" ,"#fbfaf5" ,"#d7a98c" ,"#ec6800" ,"#a8bf93" ,"#17184b" ,"#f3f3f3" ,"#f2c9ac" ,"#ec6800" ,"#769164" ,"#0d0015" ,"#f3f3f2" ,"#fff1cf" ,"#ee7800" ,"#d6e9ca" ,"#bbc8e6" ,"#eae5e3" ,"#fddea5" ,"#eb6238" ,"#93ca76" ,"#bbbcde" ,"#e5e4e6" ,"#fce2c4" ,"#ea5506" ,"#93b881" ,"#8491c3" ,"#dcdddd" ,"#fde8d0" ,"#ea5506" ,"#badcad" ,"#8491c3" ,"#dddcd6" ,"#f9c89b" ,"#eb6101" ,"#97a791" ,"#4d5aaf" ,"#c0c6c9" ,"#f7bd8f" ,"#e49e61" ,"#98d98e" ,"#4d5aaf" ,"#afafb0" ,"#f6b894" ,"#e45e32" ,"#88cb7f" ,"#4a488e" ,"#adadad" ,"#f4dda5" ,"#e17b34" ,"#69b076" ,"#4d4398" ,"#a3a3a2" ,"#f1bf99" ,"#dd7a56" ,"#6b7b6e" ,"#5654a2" ,"#9ea1a3" ,"#f1bf99" ,"#db8449" ,"#bed2c3" ,"#706caa" ,"#9fa0a0" ,"#efcd9a" ,"#d66a35" ,"#93b69c" ,"#68699b" ,"#949495" ,"#efcd9a" ,"#ffd900" ,"#a6c8b2" ,"#867ba9" ,"#888084" ,"#f0cfa0" ,"#ffd900" ,"#47885e" ,"#dbd0e6" ,"#7d7d7d" ,"#edd3a1" ,"#ffea00" ,"#316745" ,"#a59aca" ,"#7b7c7d" ,"#e0c38c" ,"#ffec47" ,"#68be8d" ,"#7058a3" ,"#727171" ,"#f3bf88" ,"#fef263" ,"#3eb370" ,"#674598" ,"#595857" ,"#f7b977" ,"#fcd575" ,"#007b43" ,"#674196" ,"#595455" ,"#f19072" ,"#fbd26b" ,"#bed3ca" ,"#9079ad" ,"#524e4d" ,"#f19072" ,"#f5e56b" ,"#92b5a9" ,"#745399" ,"#474a4d" ,"#ee836f" ,"#eec362" ,"#7ebea5" ,"#65318e" ,"#383c3c" ,"#eb9b6f" ,"#ebd842" ,"#7ebeab" ,"#522f60" ,"#2b2b2b" ,"#e0815e" ,"#ffdb4f" ,"#028760" ,"#493759" ,"#2b2b2b" ,"#df7163" ,"#fbca4d" ,"#3b7960" ,"#2e2930" ,"#180614" ,"#d57c6b" ,"#fcc800" ,"#2f5d50" ,"#884898" ,"#281a14" ,"#d0826c" ,"#f8b500" ,"#3a5b52" ,"#c0a2c7" ,"#000b00" ,"#ca8269" ,"#fabf14" ,"#475950" ,"#460e44" ,"#250d00" ,"#bb5548" ,"#f7c114" ,"#00552e" ,"#74325c" ,"#241a08" ,"#ab6953" ,"#e6b422" ,"#005243" ,"#55295b" ,"#16160e"];

    let result = "";
    let resultR = 0;
    let resultG = 0;
    let resultB = 0;
    let point = 1000000;
    
    array.forEach(function(one){
      let r2 = parseInt(one.substring(1, 3), 16);
      let g2 = parseInt(one.substring(3, 5), 16);
      let b2 = parseInt(one.substring(5, 7), 16);
      let targetPoint = Math.abs(r - r2) + Math.abs(g - g2) + Math.abs(b - b2);
      if(targetPoint < point) {
        point = targetPoint;
        result = one;
        resultR = r2;
        resultG = g2;
        resultB = b2;
      }
    });
    ctx.fillStyle = "rgba(" + resultR + "," + resultG + "," + resultB + "," + a / 255 + ")";
    ctx.fillRect(i, j, 1, 1);
}
        const diff = canvas.width - i;
    	const widthPercentage = (i / canvas.width) * 100 / 2;
    	document.getElementById('Bar').style.width = widthPercentage + '%';
    if(i == canvas.width - 1) {
      MyThread2(ctx, canvas);
    }
}

async function MyThread2(ctx2, canvas2) {
  const canvas = document.getElementById('canvas2');
  const ctx = canvas.getContext('2d', { willReadFrequently: true });
  canvas.width = canvas2.width;
  canvas.height = canvas2.height;
  for(let i = 0; i < canvas2.width; i++) {
    for(let j = 0; j < canvas2.height; j++) {
      const imageData = ctx2.getImageData(i, j, 1, 1);
      ctx.fillStyle = "rgba(" + imageData.data[0] + "," + imageData.data[1] + "," + imageData.data[2] + "," + imageData.data[3] / 255 + ")";
      ctx.fillRect(i, j, 1, 1);
    }
  }
  let resultArrayR = [];
  let resultArrayG = [];
  let resultArrayB = [];
  let resultArrayA = [];
  for(let i = 0; i < canvas.width; i++) {
  for(let j = 0; j < canvas.height; j++) {
  let arrayR = [];
  let arrayG = [];
  let arrayB = [];
  resultArrayA.push(ctx.getImageData(i, j, 1, 1).data[3]);
  for(let i2 = i - 2; i2 <= i + 2; i2++) {
  for(let j2 = j - 2; j2 <= j + 2; j2++) {
    if(i2 < 0 || canvas.width <= i2 || j2 < 0 || canvas.height <= j2) continue;
    const imageData = ctx.getImageData(i2, j2, 1, 1);
    arrayR.push(imageData.data[0]);
    arrayG.push(imageData.data[1]);
    arrayB.push(imageData.data[2]);
  }
  }
  for(let i2 = 0; i2 < arrayR.length; i2++) {
  for(let j2 = i2 + 1; j2 < arrayR.length; j2++) {
    if(arrayR[i2] + arrayG[i2] + arrayB[i2] < arrayR[j2] + arrayG[j2] + arrayB[j2]) {
      let oneTimeR = arrayR[i2];
      let oneTimeG = arrayG[i2];
      let oneTimeB = arrayB[i2];
      arrayR[i2] = arrayR[j2];
      arrayG[i2] = arrayG[j2];
      arrayB[i2] = arrayB[j2];
      arrayR[j2] = oneTimeR;
      arrayG[j2] = oneTimeG;
      arrayB[j2] = oneTimeB;
    }
  }
  }
  //console.log(arrayR.length);
  if(arrayR.length == 25) {
    resultArrayR.push(arrayR[12]);
    resultArrayG.push(arrayG[12]);
    resultArrayB.push(arrayB[12]);
  }
  else {
    resultArrayR.push(arrayR[8]);
    resultArrayG.push(arrayG[8]);
    resultArrayB.push(arrayB[8]);
  }
  if(2 < i) {
  ctx.fillStyle = "rgba(" + resultArrayR[(i - 3) * canvas.height + j] + "," + resultArrayG[(i - 3) * canvas.height + j] + "," + resultArrayB[(i - 3) * canvas.height + j] + "," + resultArrayA[(i - 3) * canvas.height + j] / 255 + ")";
  ctx.fillRect(i - 3, j, 1, 1);

  if(i == canvas.width - 1) {
  ctx.fillStyle = "rgba(" + resultArrayR[(i - 2) * canvas.height + j] + "," + resultArrayG[(i - 2) * canvas.height + j] + "," + resultArrayB[(i - 2) * canvas.height + j] + "," + resultArrayA[(i - 2) * canvas.height + j] / 255 + ")";
  ctx.fillRect(i - 2, j, 1, 1);

    ctx.fillStyle = "rgba(" + resultArrayR[(i - 1) * canvas.height + j] + "," + resultArrayG[(i - 1) * canvas.height + j] + "," + resultArrayG[(i - 1) * canvas.height + j] + "," + resultArrayA[(i - 1) * canvas.height + j] / 255 + ")";
  ctx.fillRect(i - 1, j, 1, 1);

    ctx.fillStyle = "rgba(" + resultArrayR[i * canvas.height + j] + "," + resultArrayG[i * canvas.height + j] + "," + resultArrayB[i * canvas.height + j] + "," + resultArrayA[i * canvas.height + j] / 255 + ")";
  ctx.fillRect(i, j, 1, 1);
  }
  }
  }

  const widthPercentage = (i / canvas.width + 1) * 100 / 2;
  document.getElementById('Bar').style.width = widthPercentage + '%';
  const sleep = ms => new Promise(resolve => setTimeout(resolve, ms))
  await sleep(0);
  }
}

var file = document.querySelector('#getfile');

file.onchange = function (){
  var fileList = file.files;
  //読み込み
  var reader = new FileReader();
  reader.readAsDataURL(fileList[0]); 

  //読み込み後
  reader.onload = function  () {
    document.querySelector('#preview').src = reader.result;

    const canvas2 = document.getElementById('canvas2');
    canvas2.width = 0;
    canvas2.height = 0;

    const image = document.getElementById('preview');
    const canvas = document.getElementById('canvas');
    const ctx = canvas.getContext('2d', { willReadFrequently: true });
image.onload = function() {
    canvas.width = image.width;
    canvas.height = image.height;
    ctx.drawImage(image, 0, 0);
setTimeout(() => {
  for(let i = 0; i < canvas.width; i++) {
    setTimeout(() => {
      MyThread(i, ctx, canvas);
    }, 0);
  }
}, 0);
};
};
};


</script> 
</body>
</html>

以上、画像を和色のみの構成にする
html を公開しました。

作成中のイラストの
修正アイデアとして活用して頂けると
作成した側としても非常に嬉しいです。

皆さんの開発の助けになれますように。
閲覧ありがとうございました。