From ee4acd5a8274494b4908fe1ec96bd84ca8f78d1f Mon Sep 17 00:00:00 2001
From: Pete Matsyburka <pete@docuseal.com>
Date: Wed, 25 Jun 2025 22:31:19 +0300
Subject: [PATCH] validate signature image

---
 lib/image_utils.rb | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 lib/image_utils.rb

diff --git a/lib/image_utils.rb b/lib/image_utils.rb
new file mode 100644
index 00000000..18f99ad5
--- /dev/null
+++ b/lib/image_utils.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module ImageUtils
+  module_function
+
+  def blank?(image)
+    min = (0...image.bands).map { |i| image.stats.getpoint(0, i)[0] }
+    max = (0...image.bands).map { |i| image.stats.getpoint(1, i)[0] }
+
+    return true if min.all?(255) && max.all?(255)
+    return true if min.all?(0) && max.all?(0)
+    return true if min.length >= 4 && min[-1].zero? && max[-1].zero?
+
+    false
+  end
+end