Adobe script: Selecting the most prominent color from a PSD layer

Report · Sep 01, 2023

Dear experts

Suppose I want to extract the most prominent color of an image or a photoshop layer, that is the color which is drawing the most attention, how is that possible?

I checked the following example -
Auto picking the most distinct accent color from a... - Adobe Support Community - 9875726

Here the code is picking up the average color of the image. Now this color is a mix of all the RGB components, but I want to get the most prominent color, not the average one.
Please check the attached picture; though purple is the most prominent color, the code is picking up the brown tone as the average color.

How can we enhance this?

This is the code from the above mentioned link -

var min_saturation = 50;

// create tmp layer and move it on top

app.activeDocument.artLayers.add();

if (app.activeDocument.activeLayer != app.activeDocument.layers[0]) 

    app.activeDocument.activeLayer.move(app.activeDocument.layers[0], ElementPlacement.PLACEBEFORE);

// stamp visible to tmp layer


var d = new ActionDescriptor();

d.putBoolean( charIDToTypeID( "Dplc" ), true );

executeAction( charIDToTypeID( "MrgV" ), d, DialogModes.NO );


// call hsb/hsl filter (rgb -> hsb)

var d = new ActionDescriptor();

d.putEnumerated( charIDToTypeID( "Inpt" ), charIDToTypeID( "ClrS" ), charIDToTypeID( "RGBC" ) );

d.putEnumerated( charIDToTypeID( "Otpt" ), charIDToTypeID( "ClrS" ), charIDToTypeID( "HSBl" ) ); 

executeAction( charIDToTypeID( "HsbP" ), d, DialogModes.NO );


// select "green" channel

app.activeDocument.activeChannels = [ app.activeDocument.channels[1] ];

// threshold 128 ==> saturation 50% or higher

var d = new ActionDescriptor();

d.putInteger( charIDToTypeID( "Lvl " ), min_saturation * 255/100 );

executeAction( charIDToTypeID( "Thrs" ), d, DialogModes.NO );


// selection from current channel

var r1 = new ActionReference();

r1.putProperty( charIDToTypeID( "Chnl" ), charIDToTypeID( "fsel" ) );

var d = new ActionDescriptor();

d.putReference( charIDToTypeID( "null" ), r1 );

var r2 = new ActionReference();

r2.putEnumerated( charIDToTypeID( "Chnl" ), charIDToTypeID( "Ordn" ), charIDToTypeID( "Trgt" ) );

d.putReference( charIDToTypeID( "T   " ), r2 );

executeAction( charIDToTypeID( "setd" ), d, DialogModes.NO );

// remove tmp layer

app.activeDocument.layers[0].remove();

// get average color for selection

var c = new SolidColor();

if (!get_average_color(c)) { alert("Something is wrong"); }

app.activeDocument.selection.deselect();

app.foregroundColor = c;

alert(c.rgb.red + " " +  c.rgb.green + " " + c.rgb.blue);

///////////////////////////////////////////////////////////////////////////////////

function get_average_color(color)
{
    try {
        
        var chnl = 3;
        if (app.activeDocument.mode == DocumentMode.CMYK) chnl = 4;

        if (app.activeDocument.mode == DocumentMode.GRAYSCALE) chnl = 1;

        var lm = new Array();
        var px = new Array();

        for (var i = 0; i < chnl; i++)
            {
            var hst = get_histogram(i+1);
            var l = 0;
            var p = 0;

            if (!hst) { return false; }

            for (var n in hst) { l += hst[n] * n; p += hst[n]; }  

            hst = null;

            lm.push(l);
            px.push(p);
            }

        if (app.activeDocument.mode == DocumentMode.RGB)
            {
            var r =lm[0]/px[0]; 
            var g =lm[1]/px[1]; 
            var b =lm[2]/px[2];

            with (color.rgb) { red = Math.round(r); green = Math.round(g); blue = Math.round(b); };
            }
        else if (app.activeDocument.mode == DocumentMode.LAB)
            {
            var _l = lm[0]/px[0] * 100/255; 
            var _a = lm[1]/px[1] - 128; 
            var _b = lm[2]/px[2] - 128;

            with (color.lab) { l = Math.round(_l); a = Math.round(_a); b = Math.round(_b); };
            }
        else if (app.activeDocument.mode == DocumentMode.CMYK)
            {
            var c = 100 - lm[0]/px[0] * 100/255; 
            var m = 100 - lm[1]/px[1] * 100/255; 
            var y = 100 - lm[2]/px[2] * 100/255;
            var k = 100 - lm[3]/px[3] * 100/255;

            with (color.cmyk) { cyan = Math.round(c); magenta = Math.round(m); yellow = Math.round(y); black = Math.round(k); };
            }
        else if (app.activeDocument.mode == DocumentMode.GRAYSCALE)
            {
            var _l = 100 - lm[0]/px[0] * 100/255; 

            with (color.gray) { gray = Math.round(_l);  };
            }
        else { alert("Unsupported color mode", "Error", true); return false; }

        return true;
        }
    catch (e) { alert(e); }
}

////////////////////////////////////////////////////////////
function get_histogram(n)
{
    try {
        var r = new ActionReference();
        r.putProperty(stringIDToTypeID("property"), stringIDToTypeID("histogram"));

        if (typeof(n) == "string")
            r.putName(stringIDToTypeID("channel"), n);
        else
            {
            if (app.activeDocument.mode == DocumentMode.RGB)
                {
                switch (n)
                    {       
                    case -1: r.putEnumerated(stringIDToTypeID("document"), stringIDToTypeID("ordinal"), stringIDToTypeID("targetEnum")); break;

                    case 0:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("RGB"  )); break;
                    case 1:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("red"  )); break;
                    case 2:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("green")); break;
                    case 3:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("blue" )); break;
   
                    default: r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("ordinal"), stringIDToTypeID("targetEnum")); break;
                    }
                }
            else if (app.activeDocument.mode == DocumentMode.LAB)
                {
                switch (n)
                    {
                    case -1: 
                    case 0:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("lab"      )); break;
                    case 1:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("lightness")); break;
                    case 2:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("a"        )); break;
                    case 3:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("b"        )); break;
   
                    default: r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("ordinal"), stringIDToTypeID("targetEnum")); break;
                    }
                }
            else if (app.activeDocument.mode == DocumentMode.CMYK)
                {
                switch (n)
                    {
                    case -1: r.putEnumerated(stringIDToTypeID("document"), stringIDToTypeID("ordinal"), stringIDToTypeID("targetEnum")); break;

                    case 0:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("CMYK"   )); break;
                    case 1:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("cyan"   )); break;
                    case 2:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("magenta")); break;
                    case 3:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("yellow" )); break;
                    case 4:  r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID("black"  )); break;
   
                    default: r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("ordinal"), stringIDToTypeID("targetEnum")); break;
                    }
                }
            else if (app.activeDocument.mode == DocumentMode.GRAYSCALE)
                {
                switch (n)
                    {
                    case -1: 
                    case 0:  r.putEnumerated(stringIDToTypeID("channel"),  stringIDToTypeID("channel"), stringIDToTypeID("black")); break;
   
                    default: r.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("ordinal"), stringIDToTypeID("targetEnum")); break;
                    }
                }

            else { alert("Unsupported color mode", "Error", true); return null; }
            }

        var ret;

        try { ret = executeActionGet(r).getList(stringIDToTypeID("histogram")); } catch (e) { alert(e); return null; }

        var hist = new Array();
        for (var i = 0; i < 256; i++) hist.push(ret.getInteger(i));
        // var max = Math.max.apply(null, hist);
        // alert (avg(hist));
        return hist;
        }
    catch (e) { alert(e); return null; }
}

function avg(arr) {
    var sum = 0;
 
    // Iterate the elements of the array
    for (var i = 0; i < 256; i++) {
      sum += arr[i];
    }
 
    // Returning the average of the numbers
    return sum / arr.length;
  }

Report · Sep 01, 2023

Please post the image proper.

»Color« is a problemtic term and I fear some people use it without a clear definition – which can naturally make it difficult to quantify.

What do you imagine the »most prominent color« to be in that example?

The yellow parts seem to be the most saturated ones but some people might consider some purple to be more »prominent« – in which case the next question would be: Which purple?

Report · Sep 01, 2023

Hi @c.pfaffenbichler

It may not be the exact purple, but even something closer is fine. May be average value of the all purple hues. But I don't want the average valus of the entire picture for sure.

In the present code, we are reading the histograms of all the channels.

So basically we need to decode the histogram. What should be the logic?

Thanks

Report · Sep 01, 2023

But how can you quantify that?

The purple is not the most saturated color, so how do you want to weigh hue against saturation and area and luminance etc.?

I expect scientists working on animal visual perception (humans in particular, naturally) have devised methods for evaluating images in this regard but on this Forum you may not meet those …

Report · Sep 01, 2023

I understand that, but please check the following link -

https://tympanus.net/Development/ColorExtraction/

or

https://github.com/moneypenny/steamy-screenshots

You can see they are doing the same thing. It's some sort of calculation to get the most used color pallete.

Thanks

Report · Sep 01, 2023

I understand that, but please check the following link -

https://tympanus.net/Development/ColorExtraction/

or

https://github.com/moneypenny/steamy-screenshots

You can see they are doing the same thing. It's some sort of calculation to get the most used color pallete.

Thanks

By @nirmalya123

I suspect you might be able to »borrow« something from Indexed Color – convert to a low number, then evaluate which color from the table is the most used.

Report · Sep 01, 2023

In the present code, we are reading the histograms of all the channels.

So basically we need to decode the histogram. What should be the logic?

Oh … I think there may be a misunderstanding.

The RGB Histogram (as a whole) is useless here.

Compare the histogram for the two images – they are identical but the images are not. (Edit: »almost« identical, I noticed that there are differences after all.)

Report · Sep 01, 2023

Hi @c.pfaffenbichler

Many thanks for your help.

I followed one script and as you suggested I extracted the 5 colors from the picture and created seperate layers with the rgb values. Now the picture looks like this -

Now how to check how many pixels are there for each rgb value?

If we select any rgb layer by Select -> Load Selection, we can get the area. Like this -

Can we measure this area? Then we can compare them and get the most used color.

Thanks

Report · Sep 01, 2023

This is quite a creative task that does not have an unambiguous solution unless a mathematically precise definition of what "most prominent color" means is given ¯\_(ツ)_/¯

The first thing that came to my mind was to reduce the image and use the color difference formula to calculate how much each color differs from the other. If the color difference between two pixels is less than a user-specified threshold (in this case DE_THRESHOLD = 15), then add 1 point to the pixel. Thus, the color with the highest score will be more prominent in the image.

var apl = new AM('application'),
    doc = new AM('document');
const DE_THRESHOLD = 15,
    RESIZE_TO = 35;
if (apl.getProperty('numberOfDocuments')) {
    var docRes = doc.getProperty('resolution'),
        docW = doc.getProperty('width') * docRes / 72,
        docH = doc.getProperty('height') * docRes / 72;
    doc.duplicate();
    doc.resize(docW > docH ? 'width' : 'height', RESIZE_TO)
    var f = new File(Folder.temp + '/colors.raw');
    doc.flatten();
    doc.saveToRAW(f);
    doc.close('no');
    var colors = findColors(f);
    f.remove();
    for (var i = 0; i < colors.length; i++) {
        colors[i][3] = 0;
        for (var x = 0; x < colors.length; x++) {
            if (x != i && dE(colors[i], colors[x]) <= DE_THRESHOLD) colors[i][3]++
        }
    }
    var result = 0,
        idx = null;
    for (var i = 0; i < colors.length; i++) {
        if (colors[i][3] >= result) { result = colors[i][3]; idx = i; }
    }
    var c = new SolidColor;
    c.rgb.red = colors[idx][0],
        c.rgb.green = colors[idx][1],
        c.rgb.blue = colors[idx][2];
    foregroundColor = c;
}
function findColors(f) {
    var content = '';
    if (f.exists) {
        f.open('r');
        f.encoding = "BINARY";
        content = f.read();
        f.close();
        f.remove();
        return colors = function (s) {
            var m = [],
                offset = 0;
            do {
                var c = [];
                for (i = 0; i < 3; i++) {
                    var k = s.charCodeAt(offset + i);
                    c.push(k)
                };
                m.push(c)
                offset += 3;
            } while (offset < s.length)
            return m;
        }(content);
    }
}
function dE(a, b) {
    return Math.sqrt(Math.pow(a[0] - b[0], 2) + Math.pow(a[1] - b[1], 2) + Math.pow(a[2] - b[2], 2));
}
function AM(target) {
    var s2t = stringIDToTypeID,
        t2s = typeIDToStringID,
        c2t = charIDToTypeID;
    target = target ? s2t(target) : null;
    this.getProperty = function (property, id, idxMode) {
        property = s2t(property);
        (r = new ActionReference()).putProperty(s2t('property'), property);
        id != undefined ? (idxMode ? r.putIndex(target, id) : r.putIdentifier(target, id)) :
            r.putEnumerated(target, s2t('ordinal'), s2t('targetEnum'));
        return getDescValue(executeActionGet(r), property)
    }
    this.hasProperty = function (property, id, idxMode) {
        property = s2t(property);
        (r = new ActionReference()).putProperty(s2t('property'), property);
        id ? (idxMode ? r.putIndex(target, id) : r.putIdentifier(target, id))
            : r.putEnumerated(target, s2t('ordinal'), s2t('targetEnum'));
        return executeActionGet(r).hasKey(property)
    }
    this.resize = function (dimension, value) {
        (d = new ActionDescriptor()).putUnitDouble(s2t(dimension), s2t("pixelsUnit"), value);
        d.putBoolean(s2t("constrainProportions"), true);
        d.putEnumerated(c2t("Intr"), s2t("interpolationType"), s2t("automaticInterpolation"));
        executeAction(s2t("imageSize"), d, DialogModes.NO);
    }
    this.flatten = function () {
        executeAction(s2t("flattenImage"), new ActionDescriptor(), DialogModes.NO);
    }
    this.saveToRAW = function (f) {
        (d = new ActionDescriptor()).putBoolean(s2t('copy'), true);
        (d1 = new ActionDescriptor()).putObject(s2t("as"), s2t("rawFormat"), d);
        d1.putPath(s2t("in"), f);
        executeAction(s2t("save"), d1, DialogModes.NO);
    }
    this.duplicate = function () {
        (r = new ActionReference()).putEnumerated(target, s2t("ordinal"), s2t("targetEnum"));
        (d = new ActionDescriptor()).putReference(s2t("null"), r);
        executeAction(s2t("duplicate"), d, DialogModes.NO);
    }
    this.close = function (yesNo) {
        (d = new ActionDescriptor()).putEnumerated(s2t("saving"), s2t("yesNo"), s2t(yesNo));
        executeAction(s2t("close"), d, DialogModes.NO);
    }
    function getDescValue(d, p) {
        switch (d.getType(p)) {
            case DescValueType.OBJECTTYPE: return { type: t2s(d.getObjectType(p)), value: d.getObjectValue(p) };
            case DescValueType.LISTTYPE: return d.getList(p);
            case DescValueType.REFERENCETYPE: return d.getReference(p);
            case DescValueType.BOOLEANTYPE: return d.getBoolean(p);
            case DescValueType.STRINGTYPE: return d.getString(p);
            case DescValueType.INTEGERTYPE: return d.getInteger(p);
            case DescValueType.LARGEINTEGERTYPE: return d.getLargeInteger(p);
            case DescValueType.DOUBLETYPE: return d.getDouble(p);
            case DescValueType.ALIASTYPE: return d.getPath(p);
            case DescValueType.CLASSTYPE: return d.getClass(p);
            case DescValueType.UNITDOUBLE: return (d.getUnitDoubleValue(p));
            case DescValueType.ENUMERATEDTYPE: return { type: t2s(d.getEnumerationType(p)), value: t2s(d.getEnumerationValue(p)) };
            default: break;
        };
    }
}

Screenshot 2023-09-02 005534.png

You can go further and compare groups of colors with maximum scores among themselves, finding the difference already among them (that is, find any desired number of color clusters). You can use other color models (for example, HSB to eliminate (or reduce) the influence of individual color components) and so on.

Report · Sep 02, 2023

Neat, @jazz-y !

@nirmalya123 , the following Script would get you an alert of the number on not completely transparent pixels of the pixel layers (except the Background Layer).

// 2023, use it at your own risk;
if (app.documents.length > 0) {
var myDocument = activeDocument;
var theLayers = collectPixelLayers();
alert ("the layers and their number of not completely transparent pixels\n"+theLayers.join("\n"));
};
////// load transparency //////
function loadTransparencyAsSelection (theID, theInvert) {
    var idchannel = stringIDToTypeID( "channel" );
    var desc7 = new ActionDescriptor();
        var ref3 = new ActionReference();
        ref3.putProperty( idchannel, stringIDToTypeID( "selection" ) );
    desc7.putReference( stringIDToTypeID( "null" ), ref3 );
        var ref4 = new ActionReference();
        ref4.putEnumerated( idchannel, idchannel, stringIDToTypeID( "transparencyEnum" ) );
        ref4.putIdentifier( stringIDToTypeID( "layer" ), theID );
    desc7.putReference( stringIDToTypeID( "to" ), ref4 );
    desc7.putBoolean(charIDToTypeID("Invr"), theInvert);
executeAction( stringIDToTypeID( "set" ), desc7, DialogModes.NO );
};
////// collect layers //////
function collectPixelLayers () {
// the file;
var myDocument = app.activeDocument;
// get number of layers;
var ref = new ActionReference();
ref.putProperty(stringIDToTypeID('property'), stringIDToTypeID('numberOfLayers'));
ref.putEnumerated( charIDToTypeID("Dcmn"), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") ); 
var applicationDesc = executeActionGet(ref);
var theNumber = applicationDesc.getInteger(stringIDToTypeID("numberOfLayers"));
// process the layers;
var theLayers = new Array;
for (var m = 0; m <= theNumber; m++) {
try {
var ref = new ActionReference();
ref.putIndex( charIDToTypeID( "Lyr " ), m);
var layerDesc = executeActionGet(ref);
var layerSet = typeIDToStringID(layerDesc.getEnumerationValue(stringIDToTypeID("layerSection")));
var isBackground = layerDesc.getBoolean(stringIDToTypeID("background"));
// if group collect values;
if (layerSet != "layerSectionEnd" && layerSet != "layerSectionStart" && isBackground != true) {
    if (layerDesc.getInteger(stringIDToTypeID("layerKind")) == 1) {
        var theName = layerDesc.getString(stringIDToTypeID('name'));
        var theID = layerDesc.getInteger(stringIDToTypeID('layerID'));
// get number of pixels;
        loadTransparencyAsSelection (theID, false);
        myDocument.quickMaskMode = true;
        var theHisto = myDocument.activeChannels[0].histogram;
        var thePixelNumber = 0;
        for (var x = 1; x < theHisto.length; x++) {
            thePixelNumber = thePixelNumber + theHisto[x];
        };
        myDocument.quickMaskMode = false;
        theLayers.push([theName, thePixelNumber])
    }
};
}
catch (e) {};
};
return theLayers
};

Report · Sep 02, 2023

You can go further and compare groups of colors with maximum scores among themselves, finding the difference already among them (that is, find any desired number of color clusters). You can use other color models (for example, HSB to eliminate (or reduce) the influence of individual color components) and so on.

That sounds very interesting.

In an image of a flame against a »black« background (for example) purely quantitatively »black« might be the undisputedly dominant color but many people might consider the colorful and bright element the »prominent« one, so a second evaluation with regard to saturation might be useful.

Report · Sep 02, 2023

Hi @c.pfaffenbichler and @jazz-y

Both of your answers provided me the right way. Myself and the whole community is really indebted to your knowledge and contribution.

Many thanks.

Report · Sep 03, 2023

Come to think of it CC Libraries offer something that might also be of interest to you (Extract from Image > Color Themes), but it does not seem to lend itself to automation.

Report · Sep 06, 2023

Hi @jazz-y

Please do me a little favor. Do you have the same code for each layer of a psd file?

Suppose, I have a layer set named "Group1" and it has many layers within it.

I can easily loop though the layers, but how to invoke your code for each of them?

Since this is action manager code, I am finding difficulties.

I went through your other posts and many times you have used layer as the target, but yet then I am not able to modify your code properly.

Can you please help me out?

Thanks a ton in advance ...

Report · Sep 06, 2023

Doesn’t the code @jazz-y posted set the foreground color?

Report · Sep 06, 2023

Yes, but that is for the whole document as a whole. If there are many layers, it's flattening all of them and then calculating the most prominent color. How I can do it for each individual layer?

I am close to it, but trying for the last two days!

That's my question.

Report · Sep 06, 2023

Your question seems peculiar to me.

Setting the foreground layer accordning to each layer in turn will result in the foreground color ultimately depending on the last layer alone – what good would that be?

How do you actually want to use the colors derived from each individual layer?

Report · Sep 06, 2023

Hi @c.pfaffenbichler

You are correct 🙂

But I have asked the original question for a basic example and I need to enhance this for the complete solution, which is much complex!

So I need to understand the prominent colors of each individual layers and act accordingly. So I woun't set the foreground color with those colors, but actually I will set them in different variables.

Hope this clarifies the point 🙂

Thanks again

Adobe Community

Adobe script: Selecting the most prominent color from a PSD layer

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