File use-pywavelets.patch of Package python-pyssim

From 64a58687f261eb397e9c22609b5d48497ef02762 Mon Sep 17 00:00:00 2001
From: Steve Kowalik <steven@wedontsleep.org>
Date: Thu, 6 Feb 2025 14:23:17 +1100
Subject: [PATCH] Use PyWavelets for continuous wavelet transform

scipy 1.15.0 has been released, and with it, signal.cwt has been
removed[1]. The suggested recommendation is to use PyWavelets.

1: https://docs.scipy.org/doc/scipy-1.12.0/reference/generated/scipy.signal.cwt.html
---
 requirements.txt | 1 +
 setup.py         | 2 +-
 ssim/ssimlib.py  | 6 +++---
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/setup.py b/setup.py
index bee0d6f..6ad4008 100644
--- a/setup.py
+++ b/setup.py
@@ -12,7 +12,7 @@
     author_email='jterrace@gmail.com',
     platforms=['any'],
     license='MIT License',
-    install_requires=['numpy', 'pillow', 'scipy'],
+    install_requires=['numpy', 'pillow', 'scipy', 'PyWavelets'],
     url='https://github.com/jterrace/pyssim',
     entry_points={
         'console_scripts': [
diff --git a/ssim/ssimlib.py b/ssim/ssimlib.py
index b40a8d4..46bde93 100644
--- a/ssim/ssimlib.py
+++ b/ssim/ssimlib.py
@@ -7,7 +7,7 @@
 import sys
 
 import numpy as np
-from scipy import signal
+import pywt
 
 from ssim import compat
 from ssim.compat import Image, ImageOps
@@ -168,8 +168,8 @@ def cw_ssim_value(self, target, width=30):
         sig2 = np.asarray(target.img_gray.getdata())
 
         # Convolution
-        cwtmatr1 = signal.cwt(sig1, signal.ricker, widths)
-        cwtmatr2 = signal.cwt(sig2, signal.ricker, widths)
+        cwtmatr1, freqs1 = pywt.cwt(sig1, widths, 'mexh')
+        cwtmatr2, freqs2 = pywt.cwt(sig2, widths, 'mexh')
 
         # Compute the first term
         c1c2 = np.multiply(abs(cwtmatr1), abs(cwtmatr2))