diff --git a/image_writer.c b/image_writer.c
index 2ac2c223a1..dc7ff96199 100644
--- a/image_writer.c
+++ b/image_writer.c
@@ -318,3 +318,10 @@ int write_image(struct mp_image *image, const struct image_writer_opts *opts,
 
     return success;
 }
+
+void dump_png(struct mp_image *image, const char *filename)
+{
+    struct image_writer_opts opts = image_writer_opts_defaults;
+    opts.format = "png";
+    write_image(image, &opts, filename);
+}
diff --git a/image_writer.h b/image_writer.h
index f92c2f800d..e73b526c7e 100644
--- a/image_writer.h
+++ b/image_writer.h
@@ -48,3 +48,6 @@ const char *image_writer_file_ext(const struct image_writer_opts *opts);
  */
 int write_image(struct mp_image *image, const struct image_writer_opts *opts,
                 const char *filename);
+
+// Debugging helper.
+void dump_png(struct mp_image *image, const char *filename);