Script for exporting transparent PNG files with ICC embedded

Hi,

I'm trying to create a script for Photoshop that  will convert layered tiff files to png files with transparency.

I created this script, but despite having transparency = true in the save options, the pngs are saved without transparency. They are also converted to sRGB when I want the original profile to be preserved and embedded. 

#target photoshop
app.displayDialogs = DialogModes.NO;

function convertTIFtoPNG() {
    var inputFolder = Folder.selectDialog("Select the folder containing TIFF images");
    if (!inputFolder) return; // Exit if no folder is selected

    var outputFolder = new Folder(inputFolder + "/PNG");
    if (!outputFolder.exists) outputFolder.create();

    var tifFiles = inputFolder.getFiles("*.tif");

    if (tifFiles.length === 0) {
        alert("No TIFF files found in the selected folder.");
        return;
    }

    for (var i = 0; i < tifFiles.length; i++) {
        var file = tifFiles[i];
        if (file instanceof File) {
            try {
                open(file);
                var doc = app.activeDocument;

                app.refresh();
                if (!doc) {
                    alert("Error: Document did not open properly.");
                    continue;
                }

                // Select all layers
                selectAllLayers();

                // Merge selected layers (preserving transparency)
                doc.activeLayer = doc.artLayers[0]; // Ensure a layer is active
                doc.mergeVisibleLayers();

                // Export As PNG using "Export As"
                var pngFilePath = outputFolder.fsName + "/" + file.name.replace(/\.[^\.]+$/, ".png");
                exportAsPNG(pngFilePath);

                doc.close(SaveOptions.DONOTSAVECHANGES);

            } catch (e) {
                alert("Error processing file: " + file.name + "\n" + e);
            }
        }
    }

    alert("Conversion completed! PNG files are in the 'PNG' subfolder.");
}

// Function to manually select all layers
function selectAllLayers() {
    var doc = app.activeDocument;
    var layers = doc.artLayers;
    var sets = doc.layerSets;

    if (layers.length + sets.length < 2) return; // No need to select if only one layer

    // Deselect all layers first
    doc.activeLayer = layers[layers.length - 1];

    // Select each layer manually
    for (var i = 0; i < layers.length; i++) {
        layers[i].visible = true; // Make sure all layers are visible
        layers[i].selected = true;
    }

    for (var j = 0; j < sets.length; j++) {
        selectGroupLayers(sets[j]); // Select layers inside groups
    }
}

// Function to select layers inside groups (Layer Sets)
function selectGroupLayers(layerSet) {
    for (var i = 0; i < layerSet.artLayers.length; i++) {
        layerSet.artLayers[i].visible = true;
        layerSet.artLayers[i].selected = true;
    }

    for (var j = 0; j < layerSet.layerSets.length; j++) {
        selectGroupLayers(layerSet.layerSets[j]); // Recursively select layers in nested groups
    }
}

// Function to export PNG using "Export As"
function exportAsPNG(filePath) {
    var exportOptions = new ExportOptionsSaveForWeb();
    exportOptions.format = SaveDocumentType.PNG;
    exportOptions.PNG8 = false; // Use PNG-24 for better quality
    exportOptions.transparency = true; // Preserve transparency
    exportOptions.interlaced = false;
    exportOptions.quality = 100; // Maximum quality
    exportOptions.includeProfile = true; // Embed color profile

    app.activeDocument.exportDocument(new File(filePath), ExportType.SAVEFORWEB, exportOptions);
}

convertTIFtoPNG();