diff --git a/checkbox-support/checkbox_support/scripts/psnr.py b/checkbox-support/checkbox_support/scripts/psnr.py
index 20a4707141..4929f9f015 100644
--- a/checkbox-support/checkbox_support/scripts/psnr.py
+++ b/checkbox-support/checkbox_support/scripts/psnr.py
@@ -52,33 +52,28 @@ def psnr_args() -> argparse.ArgumentParser:
     return parser.parse_args()
 
 
-def _get_psnr(I1: np.ndarray, I2: np.ndarray) -> float:
+def _get_psnr(ref_img: np.ndarray, target_img: np.ndarray) -> float:
     """
     Calculate the Peak Signal-to-Noise Ratio (PSNR) between two frames.
 
     Args:
-        I1 (np.ndarray): Reference frame.
-        I2 (np.ndarray): Frame to be compared with the reference.
+        ref_img (np.ndarray): Reference frame.
+        target_img (np.ndarray): Frame to be compared with the reference.
 
     Returns:
-        float: PSNR value indicating the quality of I2 compared to I1.
+        float: PSNR value indicating the quality of target_img compared to ref_img.
     """
     # Calculate the absolute difference
-    s1 = cv2.absdiff(I1, I2)
+    s1 = cv2.absdiff(ref_img, target_img)
     # cannot make a square on 8 bits
     s1 = np.float32(s1)
     # Calculate squared differences
     s1 = s1 * s1
-    # Sum of squared differences per channel
+    # Sum of squared differences
     sse = s1.sum()
-    # sum channels
-    if sse <= 1e-10:
-        # for small values return zero
-        return 0.0
-    else:
-        shape = I1.shape
-        mse = 1.0 * sse / (shape[0] * shape[1] * shape[2])
-        psnr = 10.0 * np.log10((255 * 255) / mse)
+    shape = ref_img.shape
+    mse = 1.0 * sse / (shape[0] * shape[1] * shape[2])
+    psnr = 10.0 * np.log10((255 * 255) / mse)
     return psnr
 
 
diff --git a/checkbox-support/checkbox_support/tests/test_psnr.py b/checkbox-support/checkbox_support/tests/test_psnr.py
index 8b2e2b9b38..5f8367efb9 100644
--- a/checkbox-support/checkbox_support/tests/test_psnr.py
+++ b/checkbox-support/checkbox_support/tests/test_psnr.py
@@ -3,6 +3,7 @@
 from unittest.mock import patch, MagicMock
 from argparse import Namespace
 from io import StringIO
+from math import inf
 
 from checkbox_support.scripts.psnr import (
     main,
@@ -60,13 +61,12 @@ def create_image(self, width, height, color):
     def test_identical_images(self):
         img1 = self.create_image(100, 100, 255)
         img2 = self.create_image(100, 100, 255)
-        self.assertEqual(_get_psnr(img1, img2), 0.0)
+        self.assertEqual(_get_psnr(img1, img2), np.float32(inf))
 
     def test_different_images(self):
         img1 = self.create_image(100, 100, 255)
         img2 = self.create_image(100, 100, 0)
-        self.assertNotEqual(_get_psnr(img1, img2), 0.0)
-        self.assertLessEqual(_get_psnr(img1, img2), 50.0)
+        self.assertEqual(_get_psnr(img1, img2), 0.0)
 
     def test_similar_images(self):
         img1 = self.create_image(100, 100, 125)