add a helper function to determine if the file is an image

app/src/main/kotlin/com/simplemobiletools/filemanager/dialogs/PropertiesDialog.kt

@@ -40,6 +40,8 @@ class PropertiesDialog : DialogFragment() {
                 properties_files_count_label.visibility = View.VISIBLE
                 properties_files_count.visibility = View.VISIBLE
                 properties_files_count.text = mFilesCnt.toString()
+            } else if (mItem.isImage()) {
+
             }
 
             val file = File(mItem.path)
@@ -47,13 +49,13 @@ class PropertiesDialog : DialogFragment() {
         }
 
         return AlertDialog.Builder(context)
-            .setTitle(resources.getString(title))
-            .setView(infoView)
-            .setPositiveButton(R.string.ok, null)
-            .create()
+                .setTitle(resources.getString(title))
+                .setView(infoView)
+                .setPositiveButton(R.string.ok, null)
+                .create()
     }
 
-    fun getItemSize(): String {
+    private fun getItemSize(): String {
         if (mItem.isDirectory) {
             mShowHidden = Config.newInstance(context).showHidden
             return getDirectorySize(File(mItem.path)).formatSize()

library/src/main/kotlin/com/simplemobiletools/filepicker/models/FileDirItem.kt

@@ -1,5 +1,7 @@
 package com.simplemobiletools.filepicker.models
 
+import android.graphics.BitmapFactory
+
 class FileDirItem(val path: String, val name: String, val isDirectory: Boolean, val children: Int, val size: Long) :
         Comparable<FileDirItem> {
 
@@ -16,4 +18,10 @@ class FileDirItem(val path: String, val name: String, val isDirectory: Boolean,
     override fun toString(): String {
         return "FileDirItem{name=$name, isDirectory=$isDirectory, path=$path, children=$children, size=$size}"
     }
+
+    fun isImage(): Boolean {
+        val options = BitmapFactory.Options()
+        options.inJustDecodeBounds = true
+        return options.outWidth !== -1 && options.outHeight !== -1
+    }
 }