Change multiple layers scale size by script

[Pubg32486011zfgs]

I wrote following photoshop script using chatGPT for change multiple layers scale size: 

// Function to resize the selected layers
function resizeSelectedLayers() {
    var doc = app.activeDocument;
    var selectedLayers = [];

    // Prompt user to select layers
    var selectedLayerIndices = prompt("Enter the indices of the layers you want to resize (comma-separated):", "");
    if (selectedLayerIndices === null || selectedLayerIndices === "") {
        alert("No layers selected.");
        return;
    }

    // Convert comma-separated indices to array
    var indicesArray = selectedLayerIndices.split(",");
    for (var i = 0; i < indicesArray.length; i++) {
        var index = parseInt(indicesArray[i]);
        if (!isNaN(index) && index >= 0 && index < doc.layers.length) {
            selectedLayers.push(doc.layers[index]);
        } else {
            alert("Invalid layer index: " + indicesArray[i]);
            return;
        }
    }

    // Check if there are selected layers
    if (selectedLayers.length > 0) {
        // Loop through each selected layer
        for (var j = 0; j < selectedLayers.length; j++) {
            var selectedLayer = selectedLayers[j];
            doc.activeLayer = selectedLayer;

            // Calculate scaling factor
            var scalePercentage = 76.39; // Percentage size
            var scaleFactor = scalePercentage / 100;

            // Get current dimensions
            var width = selectedLayer.bounds[2] - selectedLayer.bounds[0];
            var height = selectedLayer.bounds[3] - selectedLayer.bounds[1];

            // Calculate new dimensions with locked aspect ratio
            var newWidth = width * scaleFactor;
            var newHeight = height * scaleFactor;

            // Calculate the scaling ratio
            var ratio = newWidth / width;

            // Set up the transformation
            var desc = new ActionDescriptor();
            var ref = new ActionReference();
            ref.putEnumerated(charIDToTypeID('Lyr '), charIDToTypeID('Ordn'), charIDToTypeID('Trgt'));
            desc.putReference(charIDToTypeID('null'), ref);

            // Set transformation parameters
            desc.putEnumerated(charIDToTypeID('FTcs'), charIDToTypeID('QCSt'), charIDToTypeID('Qcsa'));
            desc.putUnitDouble(charIDToTypeID('Wdth'), charIDToTypeID('#Prc'), 100 * ratio);
            desc.putUnitDouble(charIDToTypeID('Hght'), charIDToTypeID('#Prc'), 100 * ratio);
            desc.putEnumerated(charIDToTypeID('Intr'), charIDToTypeID('Intp'), charIDToTypeID('Bcbc'));

            // Execute transformation
            executeAction(charIDToTypeID('Trnf'), desc, DialogModes.NO);
        }
    } else {
        alert("Please select one or more layers.");
    }
}

// Check if there is an active document
if (app.documents.length > 0) {
    // Call the resizeSelectedLayers function
    resizeSelectedLayers();
} else {
    alert("No documents are open.");
}

The script above is functioning well, but it doesn't provide accurate results. For instance, it's expected to change both the width (W) and height (H) to a scale size of 76.39%. However, during testing, I noticed that the width changed to 76.92% and the height changed to 75.76%.

What could be causing this discrepancy in the script? It's worth noting that maintaining the aspect ratio is essential.

[Stephen Marsh]

I tested with a 10K square pixel layer and all was good – 7639 px for both width and height.

If you are transforming a rectangular layer, then you may get some rounding depending on the original pixel values and how these are scaled via %.

[Stephen Marsh]

You could also try an alternative script to see if you get the same or different result:

/*
Scale Selected Layers Independently v1.jsx
26th August 2022, Stephen Marsh
https://community.adobe.com/t5/photoshop-ecosystem-discussions/how-do-i-scale-multiple-layers-while-keeping-them-anchored-in-place/td-p/13157052
*/

#target photoshop

////////// SCRIPT UI START //////////

/*
With thanks - https://scriptui.joonas.me
*/

// DIALOG
var theGUI = new Window("dialog");
    theGUI.text = "Scale Selected Layers Independently - v1.0";
    theGUI.orientation = "row";
    theGUI.alignChildren = ["center","top"];
    theGUI.spacing = 10;
    theGUI.margins = 20;

var scaleLabel = theGUI.add("statictext", undefined, undefined, {name: "scaleLabel"});
    scaleLabel.text = "Scale %";

// SCALE GROUP
var scaleGroup = theGUI.add("group", undefined, {name: "scaleGroup"});
    scaleGroup.orientation = "row";
    scaleGroup.alignChildren = ["left","center"];
    scaleGroup.spacing = 10;
    scaleGroup.margins = 0;

// SCALE WIDTH GROUP
var scaleWidthGroup = scaleGroup.add("group", undefined, {name: "scaleWidthGroup"});
    scaleWidthGroup.orientation = "column";
    scaleWidthGroup.alignChildren = ["left","center"];
    scaleWidthGroup.spacing = 10;
    scaleWidthGroup.margins = 0;

    var widthLabel = scaleWidthGroup.add("statictext", undefined, undefined, {name: "widthLabel"});
    widthLabel.text = "Width:";

    ////////// Use editnumber instead of edittext for numerical fields! //////////
    var widthField = scaleWidthGroup.add('editnumber {properties: {name: "widthField"}}');
        widthField.text = "76.39";
    widthField.preferredSize.width = 50;
   
    ////////// Preset the width field as active - Peter Kahrel, scriptUI for dummies //////////
    widthField.active = true;
    ////////// Initially use the width value for the height value //////////
    ////////// Callback: onChange - Peter Kahrel, scriptUI for dummies //////////
    widthField.onChange = function () {heightField.text = widthField.text}
    //////////

// SCALE HEIGHT GROUP
var scaleHeightGroup = scaleGroup.add("group", undefined, {name: "scaleHeightGroup"});
    scaleHeightGroup.orientation = "column";
    scaleHeightGroup.alignChildren = ["left","center"];
    scaleHeightGroup.spacing = 10;
    scaleHeightGroup.margins = 0;

var heightLabel = scaleHeightGroup.add("statictext", undefined, undefined, {name: "heightLabel"});
    heightLabel.text = "Height:";

////////// Use editnumber instead of edittext for numerical fields! //////////
var heightField = scaleHeightGroup.add('editnumber {properties: {name: "heightField"}}');
    heightField.text = "76.39";
    heightField.preferredSize.width = 50;

// DIVIDER 1
//var divOne = scaleGroup.add("panel", undefined, undefined, {name: "divOne"});
    //divOne.alignment = "fill";

// RADIO PARENT GROUP
var radioGroup = theGUI.add("group", undefined, {name: "radioGroup"});
    radioGroup.orientation = "row";
    radioGroup.alignChildren = ["left","center"];
    radioGroup.spacing = 10;
    radioGroup.margins = 0;

// RADIO GROUP LEFT
var radioGroupLeft = radioGroup.add("group", undefined, {name: "radioGroupLeft"});
    radioGroupLeft.orientation = "column";
    radioGroupLeft.alignChildren = ["left","center"];
    radioGroupLeft.spacing = 10;
    radioGroupLeft.margins = 0;

var topLeft = radioGroupLeft.add("radiobutton", undefined, undefined, {name: "topLeft"});
    topLeft.text = "TL";

var middleLeft = radioGroupLeft.add("radiobutton", undefined, undefined, {name: "middleLeft"});
    middleLeft.text = "ML";

var bottomLeft = radioGroupLeft.add("radiobutton", undefined, undefined, {name: "bottomLeft"});
    bottomLeft.text = "BL";

// RADIO GROUP CENTER
var radioGroupCenter = radioGroup.add("group", undefined, {name: "radioGroupCenter"});
    radioGroupCenter.orientation = "column";
    radioGroupCenter.alignChildren = ["left","center"];
    radioGroupCenter.spacing = 10;
    radioGroupCenter.margins = 0;

var topCenter = radioGroupCenter.add("radiobutton", undefined, undefined, {name: "topCenter"});
    topCenter.text = "TC";

var middleCenter = radioGroupCenter.add("radiobutton", undefined, undefined, {name: "middleCenter"});
    middleCenter.text = "MC";
    ////////// Preset the radio button as active - Peter Kahrel, scriptUI for dummies //////////
    middleCenter.value = true;
    //////////

var bottomCenter = radioGroupCenter.add("radiobutton", undefined, undefined, {name: "bottomCenter"});
    bottomCenter.text = "BC";

// RADIO GROUP RIGHT
var radioGroupRight = radioGroup.add("group", undefined, {name: "radioGroupRight"});
    radioGroupRight.orientation = "column";
    radioGroupRight.alignChildren = ["left","center"];
    radioGroupRight.spacing = 10;
    radioGroupRight.margins = 0;

    var topRight = radioGroupRight.add("radiobutton", undefined, undefined, {name: "topRight"});
        topRight.text = "TR";

    var middleRight = radioGroupRight.add("radiobutton", undefined, undefined, {name: "middleRight"});
        middleRight.text = "MR";

    var bottomRight = radioGroupRight.add("radiobutton", undefined, undefined, {name: "bottomRight"});
    bottomRight.text = "BR";
   
    ////////// Make multiple groups act as one group - Peter Kahrel, scriptUI for dummies //////////
    radioGroupLeft.addEventListener("click", function () {
        for (var i = 0; i < radioGroupCenter.children.length; i++)
            radioGroupCenter.children[i].value = false;
    });
    radioGroupLeft.addEventListener("click", function () {
        for (var i = 0; i < radioGroupRight.children.length; i++)
            radioGroupRight.children[i].value = false;
    });
    radioGroupCenter.addEventListener("click", function () {
        for (var i = 0; i < radioGroupLeft.children.length; i++)
            radioGroupLeft.children[i].value = false;
    });
    radioGroupCenter.addEventListener("click", function () {
        for (var i = 0; i < radioGroupRight.children.length; i++)
            radioGroupRight.children[i].value = false;
    });
    radioGroupRight.addEventListener("click", function () {
        for (var i = 0; i < radioGroupCenter.children.length; i++)
            radioGroupCenter.children[i].value = false;
    });
    radioGroupRight.addEventListener("click", function () {
        for (var i = 0; i < radioGroupLeft.children.length; i++)
            radioGroupLeft.children[i].value = false;
    });
    //////////

// DIVIDER 2
//var divTwo = theGUI.add("panel", undefined, undefined, {name: "divTwo"});
    //divTwo.alignment = "fill";

// BUTTON GROUP
var buttonGroup = theGUI.add("group", undefined, {name: "buttonGroup"});
    buttonGroup.orientation = "column";
    buttonGroup.alignChildren = ["left","center"];
    buttonGroup.spacing = 10;
    buttonGroup.margins = 0;

var okButton = buttonGroup.add("button", undefined, undefined, {name: "okButton"});
    okButton.text = "OK";
    okButton.alignment = ["fill","center"];

var cancelButton = buttonGroup.add("button", undefined, undefined, {name: "cancelButton"});
    cancelButton.text = "Cancel";
    cancelButton.alignment = ["fill", "center"];

// RENDER THE DIALOG
theGUI.show();

////////// SCRIPT UI END //////////


function main() {

            var s2t = stringIDToTypeID;
            (r = new ActionReference).putProperty(s2t('property'), p = s2t('targetLayersIDs'));
            r.putEnumerated(s2t('document'), s2t('ordinal'), s2t('targetEnum'));
            var lrs = executeActionGet(r).getList(p),
                sel = new ActionReference();

            for (var i = 0; i < lrs.count; i++) {
                sel.putIdentifier(s2t('layer'), p = lrs.getReference(i).getIdentifier(s2t('layerID')));
                (r = new ActionReference).putIdentifier(s2t('layer'), p);
                (d = new ActionDescriptor()).putReference(s2t("target"), r);
                executeAction(s2t('select'), d, DialogModes.NO);
               
                ////////// Link the radio buttons to the resize  //////////
                if (topLeft.value === true) {
                    activeDocument.activeLayer.resize(widthField.text, heightField.text, AnchorPosition.TOPLEFT);
                }
                if (topCenter.value === true) {
                    activeDocument.activeLayer.resize(widthField.text, heightField.text, AnchorPosition.TOPCENTER);
                }
                if (topRight.value === true) {
                    activeDocument.activeLayer.resize(widthField.text, heightField.text, AnchorPosition.TOPRIGHT);
                }
                if (middleLeft.value === true) {
                    activeDocument.activeLayer.resize(widthField.text, heightField.text, AnchorPosition.MIDDLELEFT);
                }
                if (middleCenter.value === true) {
                    activeDocument.activeLayer.resize(widthField.text, heightField.text, AnchorPosition.MIDDLECENTER);
                }
                if (middleRight.value === true) {
                    activeDocument.activeLayer.resize(widthField.text, heightField.text, AnchorPosition.MIDDLERIGHT);
                }
                if (bottomLeft.value === true) {
                    activeDocument.activeLayer.resize(widthField.text, heightField.text, AnchorPosition.BOTTOMLEFT);
                }
                if (bottomCenter.value === true) {
                    activeDocument.activeLayer.resize(widthField.text, heightField.text, AnchorPosition.BOTTOMCENTER);
                }
                if (bottomRight.value === true) {
                    activeDocument.activeLayer.resize(widthField.text, heightField.text, AnchorPosition.BOTTOMRIGHT);
                }
            }
}

activeDocument.suspendHistory("Scale Selected Layers Independently.jsx", "main()");

[Pubg32486011zfgs]

tnq but it not working and i still have that problem!

[Stephen Marsh]

Perhaps if you supplied detailed pertinent information...

[r-bin]

I think it's just a Photoshop glitch. Transformation of selected smart objects fails. The screenshot (CS6) shows the transformation of two identical selected smart objects from 100% to 9% percent. It can be seen that the transformation boundary and the boundaries of the objects themselves do not coincide in this process.

[Pubg32486011zfgs]

oh no - photoshop team must fix this issue!