Skip to content Skip to sidebar Skip to footer

Colorize Or Replace The Color Of A Textured Image By A Specified Color Using Javascript And Html5 Canvas.like Color Blend Mode In Ps

I have a textured image with color. What i want is to change the color of the image but retaining its texture. i already know how to get the data of an image,pixel by pixel(the rg

Solution 1:

Here's an interactive solution. Run it from localhost and specify a valid image.

enter image description here

<!DOCTYPE html><html><head><script>functionbyId(e){returndocument.getElementById(e);}
functionnewEl(tag){returndocument.createElement(tag);}
functionnewTxt(txt){returndocument.createTextNode(txt);}

window.addEventListener('load', mInit, false);

functionmInit()
{
    var srcImg = byId('srcImg');

    byId('hueSlider').style.width = srcImg.width + "px";
    var destImg = byId('dstImg');
    destImg.width = srcImg.width;
    destImg.height = srcImg.height;
}

functioncolorize()
{
    var curHue = byId('hueSlider').value;
    var curSat = byId('satSlider').value;// / 100.0;var curLum = byId('lumSlider').value / 100.0;
    byId('hueVal').innerHTML = curHue;
    byId('satVal').innerHTML = curSat;
    byId('lumVal').innerHTML = curLum;

    var dst = byId('dstImg');
    var dstCtx = dst.getContext('2d');
    var img = byId('srcImg');
    dstCtx.drawImage(img, 0, 0);

    var dstImgData = dstCtx.getImageData(0,0,dst.width,dst.height);
    var i, j, r,g,b,hsl,rgb, index;
    if (byId('colCheckBox').checked)
    {
        console.log('colourizing');
        for (j=0; j<dst.height; j++)
        {
            for (i=0; i<dst.width; i++)
            {
                index = (i + j*dst.width) * 4;              // 4 bytes/pixel, set index to point to r component of x,y in dst image
                r = dstImgData.data[index+0];
                g = dstImgData.data[index+1];
                b = dstImgData.data[index+2];
                hsl = rgb2hsl (r, g, b);

                hsl.h = curHue;
                //if (hsl.h > 359)//  hsl.h -= 360;
                hsl.s = curSat;

                hsl.l *= curLum;

                rgb = hsl2rgb(hsl.h, hsl.s, hsl.l);
                dstImgData.data[index+0] = rgb.r;
                dstImgData.data[index+1] = rgb.g;
                dstImgData.data[index+2] = rgb.b;
            }
        }
        dstCtx.putImageData(dstImgData,0,0);
    }
}

// code taken from nichabi.comfunctionhsl2rgb (h, s, l) {

    var r, g, b, m, c, x

    if (!isFinite(h)) h = 0if (!isFinite(s)) s = 0if (!isFinite(l)) l = 0

    h /= 60if (h < 0) h = 6 - (-h % 6)
    h %= 6

    s = Math.max(0, Math.min(1, s / 100))
    l = Math.max(0, Math.min(1, l / 100))

    c = (1 - Math.abs((2 * l) - 1)) * s
    x = c * (1 - Math.abs((h % 2) - 1))

    if (h < 1) {
        r = c
        g = x
        b = 0
    } elseif (h < 2) {
        r = x
        g = c
        b = 0
    } elseif (h < 3) {
        r = 0
        g = c
        b = x
    } elseif (h < 4) {
        r = 0
        g = x
        b = c
    } elseif (h < 5) {
        r = x
        g = 0
        b = c
    } else {
        r = c
        g = 0
        b = x
    }

    m = l - c / 2
    r = Math.round((r + m) * 255)
    g = Math.round((g + m) * 255)
    b = Math.round((b + m) * 255)

    return { r: r, g: g, b: b }
}


// code taken from nichabi.comfunctionrgb2hsl (r, g, b) 
{
    var max, min, h, s, l, d
    r /= 255
    g /= 255
    b /= 255
    max = Math.max(r, g, b)
    min = Math.min(r, g, b)
    l = (max + min) / 2if (max == min) {
        h = s = 0
    } else {
        d = max - min
        s = l > 0.5 ? d / (2 - max - min) : d / (max + min)
        switch (max) {
            caser:
                h = (g - b) / d + (g < b ? 6 : 0)
                breakcaseg:
                h = (b - r) / d + 2breakcaseb:
                h = (r - g) / d + 4break
        }
        h /= 6
    }
    h = Math.floor(h * 360)
    s = Math.floor(s * 100)
    l = Math.floor(l * 100)
    return { h: h, s: s, l: l }
}


</script><style>body
{
    background: #888;
}
#hueVal, #satVal, #lumVal
{
    font-size: 0.8em;
    font-weight: bold;
    display: inline;
}
</style></head><body><imgid='srcImg'src='handlebars.png'/><canvasid='dstImg'></canvas><br><label><inputtype='checkbox'id='colCheckBox'onchange='colorize()' />Colourize</label><br>
Hue<inputid='hueSlider'onchange='colorize()'type='range'min='0'max='359'/><divid='hueVal'></div><br>
Saturation<inputid='satSlider'onchange='colorize()'type='range'value='50'min='0'max='100'/><divid='satVal'></div><br>
Luminance<inputid='lumSlider'onchange='colorize()'type='range'min='0'max='200'/><divid='lumVal'></div></body></html>

Post a Comment for "Colorize Or Replace The Color Of A Textured Image By A Specified Color Using Javascript And Html5 Canvas.like Color Blend Mode In Ps"