javascript - 在图像中查找特定颜色

标签 javascript jquery html image

我有这样一张图片:

Image 1

并喜欢在图像中找到特定颜色 (#ffa400/#ffffff) 并获取它们的出现百分比值(橙色可能是:75%,白色:25%)

NOTE: Keep in mind that I don't like to get the average color (in this case: orange) like Color Thief does, but I'D like to find a SPECIFIC color.


下面是一个片段,所以这就是我到目前为止所得到的全部内容,但代码似乎无法正常工作,而且我的想法似乎也不是一种高效且快速的方法。

function extract_colors(img) {
    var canvas = document.createElement("canvas");
    var c = canvas.getContext('2d');
    c.width = canvas.width = img.width;
    c.height = canvas.height = img.height;
    c.clearRect(0, 0, c.width, c.height);
    c.drawImage(img, 0, 0, img.width, img.height);
    return getColors(c);

}

function getColors(c) {
    var col, colors = {};
    var pixels, r, g, b, a;
    r = g = b = a = 0;
    pixels = c.getImageData(0, 0, c.width, c.height);
    for (var i = 0, data = pixels.data; i < data.length; i + = 4) {
        r = data[i];
        g = data[i + 1];
        b = data[i + 2];
        a = data[i + 3];
        if (a < (255 / 2))
            continue;
        col = rgbToHex(r, g, b);
        if (col == 'ffa400') { // find color #ffa400
            if (!colors[col])
                colors[col] = 0;
            colors[col] + +;
        }
    }
    return colors;
}


function rgbToHex(r, g, b) {
    return ((r << 16) | (g << 8) | b).toString(16);
}

var img = document.getElementById('img');
out.innerHTML = extract_colors(img)
<img id='img' width=100 src='/image/EPDlQ.png'>

<p id='out'>...</p>

EDIT 1.0

我正在尝试使用这样的代码,但它似乎也不起作用。

var orangeMatches=0, whiteMatches=0
        Jimp.read("/image/EPDlQ.png").then(function (image) {
            image.scan(0, 0, image.bitmap.width, image.bitmap.height, function (x, y, idx) {
              var red   = this.bitmap.data[ idx + 0 ];
              var green = this.bitmap.data[ idx + 1 ];
              var blue  = this.bitmap.data[ idx + 2 ];
              var alpha = this.bitmap.data[ idx + 3 ];

              if (red == 255 && green == 164 && blue == 0 && alpha == 1){
                orangeMatches++;
              }
              if (red == 255 && green == 255 && blue == 255 && alpha == 1){
                whiteMatches++;
              }
          });
          console.log(orangeMatches, whiteMatches)
        });

Edit 2.0

我想要某种容忍值 (10%),这样就不会计算每种颜色,而是将匹配在一起的颜色(例如 #ffa400 #ffa410)计算在一起。

最佳答案

一些注意事项

你图片的主色其实是ffa500,不是ffa400。实际上根本没有出现 ffa400。

另请记住,这是一个消除锯齿的位图图形。在视觉上我们只能看到两种颜色,但是为了平滑从一种颜色到另一种颜色的过渡,生成了一组“中间色”。换句话说,ffffff 和 ffa500 的总和不会正好是 100%。 (这就是为什么我下面的函数的输出将显示比所讨论的两个更多的颜色)


解决方案一

该解决方案的基本思想是获取图片中的每种颜色,将它们存储在一个公共(public)对象中,在该对象中计算每种颜色的出现次数。返回此对象后,我们可以稍后计算输出中某些特定颜色的出现次数。

这将返回如下内容:

{
    ffa500: 7802,
    ffa501: 4,
    ffa502: 2,
    ...,
    ffffff: 1919,
    total: 10000
}

现在您可以通过这种方式访问​​给定颜色的出现:

var imageData = extract_colors(img),
    white = imageData.ffffff,
    total = imageData.total;

要显示给定颜色覆盖图像的百分比,请执行以下操作(toFixed() 只是将值限制为两位小数):

whitePct = (white / total * 100).toFixed(2);

工作样本

function getColors(ctx) {

		// Get the canvas data
    var pixels = ctx.getImageData(0, 0, ctx.width, ctx.height),
        data = pixels.data,
        
        // Set up our output object to collect color data
        output = {};
    
    // For each color we encounter, check the
    // output object. If the color already exists
    // there, simply increase its counted value.
    // If it does not, create a new key.
    for (var i = 0; i < data.length; i+=4) {
        var r = data[i],
            g = data[i + 1],
            b = data[i + 2],
            col = rgbToHex(r, g, b);

        if( output[col] )
        	output[col]++
        else
        	output[col] = 1
    }
    
    // Count total
    var total = 0;
    for(var key in output) {
    	total = total + parseInt(output[key])
    }
    output.total = total;
    
    // Return the color data as an object
    return output;
}

// Our elements
var img = document.getElementById('img'),
	  out = document.getElementById('out');

// Retrieve the image data
var imageData = extract_colors(img),

    // Count our given colors
    white = imageData.ffffff,
    orange = imageData.ffa500,
    total = imageData.total,

    // Calculate percentage value
    whitePct = (white / total * 100).toFixed(2),
    orangePct = (orange / total * 100).toFixed(2);
  
out.innerHTML = `White: ${whitePct}%<br/>Orange: ${orangePct}%`;

// See the console for all colors identified
console.log(extract_colors(img))

// ----- These functions are left untouched ----- \\

function extract_colors(img) {
    var canvas = document.createElement("canvas");
    var c = canvas.getContext('2d');
    c.width = canvas.width = img.width;
    c.height = canvas.height = img.height;
    c.clearRect(0, 0, c.width, c.height);
    c.drawImage(img, 0, 0, img.width, img.height);
    return getColors(c);
}

function rgbToHex(r, g, b) {
    return ((r << 16) | (g << 8) | b).toString(16);
}
p, img {
 margin: 10px 5px;
 float: left
}
<!-- Image converted to base64 to keep it locally availible -->
<img id='img' width=100 src='data:image/png;base64,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'>
<p id='out'>...</p>


方案二

(将此解决方案视为草稿。如果要用于实时网站,可能需要进行一些调整,但至少它应该可以工作!)

这里的想法是调用 extract_colors() 并将我们想要映射的颜色作为参数。构建了一个通用对象来保存输出,并为每种颜色填充了一个对象。颜色对象由一个计数器和一个 rgb 值组成。使用 isNeighborColor() 函数,rgb 值不仅用于匹配特定颜色,还用于匹配任何接近它的颜色。根据需要调整容差级别。 (理想情况下,我猜这将是另一个论点)。

调用指定图像和计算出现次数的颜色的函数:

var imageData = extract_colors(img, 'ffffff', 'ffa500'),

这将为每种颜色输出一个对象:

{
  "ffffff": {
    "counter": 1979,
    "rgb": {
      "r": 255,
      "g": 255,
      "b": 255
    }
  },
  "ffa500": {
    "counter": 7837,
    "rgb": {
      "r": 255,
      "g": 165,
      "b": 0
    }
  },
  "total": 9816
}

我们想要的是访问计数器值:

var white = imageData.ffffff.counter;

工作样本

// Added a rest parameter for unlimited color input
function extract_colors(img, ...colors) {
    var canvas = document.createElement("canvas");
    var c = canvas.getContext('2d');
    c.width = canvas.width = img.width;
    c.height = canvas.height = img.height;
    c.clearRect(0, 0, c.width, c.height);
    c.drawImage(img, 0, 0, img.width, img.height);
    return getColors(c, ...colors);
}

// Unchanged
function rgbToHex(r, g, b) {
    return ((r << 16) | (g << 8) | b).toString(16);
}

// From: https://stackoverflow.com/a/5624139/2311559
function hexToRgb(hex) {
    var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
    return result ? {
        r: parseInt(result[1], 16),
        g: parseInt(result[2], 16),
        b: parseInt(result[3], 16)
    } : null;
}

// From: https://stackoverflow.com/a/11506531/2311559
// Slightly modified
function isNeighborColor(color1, color2, tolerance) {
    tolerance = tolerance || 32;
    return Math.abs(color1.r - color2.r) <= tolerance
        && Math.abs(color1.g - color2.g) <= tolerance
        && Math.abs(color1.b - color2.b) <= tolerance;
}

function getColors(ctx, ...colors) {

		var pixels = ctx.getImageData(0, 0, ctx.width, ctx.height),
        data = pixels.data,
        output = {};
    
    // Build an 'output' object. This will hold one object for
    // each color we want to check. The color objects will 
    // each consist of a counter and an rgb value. The counter 
    // is used to count the occurrence of each color. The rgb 
    // value is used to match colors with a certain tolerance 
    // using the 'isNeighborColor()' function above.
    for (var i = 0; i < colors.length; i++) {
        output[colors[i]] = {
        	counter: 0,
          rgb: hexToRgb(colors[i])
        };
    }

    // For each pixel, match its color against the colors in our
    // 'output' object. Using the 'isNeighborColor()' function 
    // we will also match colors close to our input, given the 
    // tolerance defined.
    for (var i = 0; i < data.length; i+=4) {
        var r = data[i],
            g = data[i + 1],
            b = data[i + 2],
            colobj = {r, g, b},
            col = rgbToHex(r, g, b);

        Object.keys(output).map(function(objectKey, index) {
            var rgb = output[objectKey].rgb,
            		count = output[objectKey].counter;
            if(isNeighborColor(rgb, colobj)) {
            	output[objectKey].counter = count+1;
            }
        });

    }
    
    // Count total
    var total = 0;
    for(var key in output) {
    	total = total + parseInt(output[key].counter)
    }
    output.total = total;
    
    // Return the color data as an object
    return output;
}

// Our elements
var img = document.getElementById('img'),
	  out = document.getElementById('out');

// Retrieve the image data
var imageData = extract_colors(img,'ffffff','ffa500'),

    // Count our given colors
    white = imageData.ffffff.counter,
    orange = imageData.ffa500.counter,
    total = imageData.total,

    // Calculate percentage value
    whitePct = (white / total * 100).toFixed(2),
    orangePct = (orange / total * 100).toFixed(2);

out.innerHTML = `White: ${whitePct}%<br/>Orange: ${orangePct}%`;

// Optional console output
console.log(extract_colors(img,'ffffff','ffa500'));
p, img {
 margin: 10px 5px;
 float: left
}
<!-- Image converted to base64 to keep it locally availible -->
<img id='img' width=100 src='data:image/png;base64,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'>
<p id='out'>...</p>

关于javascript - 在图像中查找特定颜色,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/47608864/

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