I have used same 9 patch image in drawable folder where it was working fine but when i saved it in internal storage it is treated as regular image with black lines(of 9-patch tool) shown in image.

public static Drawable getImageDrawable(Context context, String themeName, String imageName) {
        File themeDir = new File(context.getFilesDir(), THEME_DIR);
        File themeSubDir = new File(themeDir, themeName);
        if (themeSubDir.exists() && themeSubDir.isDirectory()) {
            File imageFile = new File(themeSubDir, imageName);
            if (imageFile.exists() && imageFile.isFile()) {
                if (imageName.endsWith(".9.png")) {
                    return getNinePatchDrawable(context, imageFile);
                } else {
                    return Drawable.createFromPath(imageFile.getAbsolutePath());
                }
            }
        }
        return null; // Return null if the file does not exist
    }
    private static Drawable getNinePatchDrawable(Context context, File imageFile) {
        try  {
            FileInputStream fis = new FileInputStream(imageFile);
            Bitmap bitmap = BitmapFactory.decodeStream(fis);

            if (bitmap != null) {

                byte[] chunk = bitmap.getNinePatchChunk();
                if (chunk != null) {
                    String chunkData = new String(chunk, StandardCharsets.UTF_8);
                    Log.d("TAG", "Chunk data: " + chunkData);
                }
                if (NinePatch.isNinePatchChunk(chunk)) {
                    Rect padding = new Rect();
                    NinePatchDrawable ninePatchDrawable = new NinePatchDrawable(context.getResources(), bitmap, chunk, padding, null);
                    return ninePatchDrawable;
                } else {
                    Log.e("CheckPoint1", "The chunk is not a valid nine-patch chunk: " + imageFile.getAbsolutePath());
                }
            } else {
                Log.e("CheckPoint2", "Bitmap could not be decoded: " + imageFile.getAbsolutePath());
            }
        } catch (Exception e) {
            Log.e("CheckPoint3", "Error reading image file: " + imageFile.getAbsolutePath(), e);
        }
        return null;
    }

in case of 9-patch images it always ends at checkPoint1, i have tried many images. when i use drawable class it shows image but content and stretching area is works as regular image but when i saved these images in drawable folder to check whether image is faulty, i got all the images fine.