From 95be9dd632c938cfd4695fe7481f2acb464ea8fe Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Fri, 29 May 2026 10:11:11 +0200
Subject: [PATCH] [conv2d] - add 2D convolution function and test

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/rbm/image.py         | 26 ++++++++++++++++++++++++++
 src/tests/test_conv2d.py | 12 ++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 src/tests/test_conv2d.py

diff --git a/src/rbm/image.py b/src/rbm/image.py
index 83d8d44..05839af 100644
--- a/src/rbm/image.py
+++ b/src/rbm/image.py
@@ -48,3 +48,29 @@ class SubImage:
 					k += 1
 
 		return result
+
+def conv2d(image: Mat, kernel: Mat, stride: tuple[int,int]):
+	pad_x = int((kernel.shape[0] - 1)/2)
+	pad_y = int((kernel.shape[1] - 1)/2)
+	image_padded = np.pad(image, pad_width=(pad_x, pad_y))
+
+	nx = (image_padded.shape[0] - kernel.shape[0])
+	ny = (image_padded.shape[1] - kernel.shape[1])
+	if nx % stride[0]:
+		raise ValueError
+	if ny % stride[1]:
+		raise ValueError
+	pass
+
+	result = np.zeros((image_padded.shape[0] + kernel.shape[0] - 1, image_padded.shape[1] + kernel.shape[1] - 1))
+	k = 0
+	for r in range(pad_y, image_padded.shape[0]-pad_y):
+		result[r,:] = np.convolve(image_padded[r,:], kernel[k,:])
+		k += 1
+
+	k = 0
+	for c in range(pad_x, image_padded.shape[1]-pad_x):
+		result[:, c] += np.convolve(image_padded[:,c], kernel[:,k])
+		k += 1
+
+	return result
diff --git a/src/tests/test_conv2d.py b/src/tests/test_conv2d.py
new file mode 100644
index 0000000..3bb30cb
--- /dev/null
+++ b/src/tests/test_conv2d.py
@@ -0,0 +1,12 @@
+from rbm.image import conv2d
+from rbm.matrix import np
+
+
+if __name__ == "__main__":
+	A = np.random.rand(3, 3)
+	K = np.random.rand(3, 3)
+
+	y = conv2d(A, K, (1,1))
+	print(y)
+
+	print("Test: [passed]")