From dce2a1a0282c203ad391b23d9a11a47736cade07 Mon Sep 17 00:00:00 2001
From: Max Jones <14077947+maxrjones@users.noreply.github.com>
Date: Fri, 30 May 2025 15:49:12 -0400
Subject: [PATCH] Define codec for LZW compression

---
 codecs/lzw/README.md   | 37 +++++++++++++++++++++++++++++++++++++
 codecs/lzw/schema.json | 16 ++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 codecs/lzw/README.md
 create mode 100644 codecs/lzw/schema.json

diff --git a/codecs/lzw/README.md b/codecs/lzw/README.md
new file mode 100644
index 0000000..8915a1e
--- /dev/null
+++ b/codecs/lzw/README.md
@@ -0,0 +1,37 @@
+# lzw codec
+
+Defines a `bytes -> bytes` codec that applies [LZW (Lempel-Ziv-Welch) compression](https://ieeexplore.ieee.org/document/1659158).
+
+## Codec name
+
+The value of the `name` member in the codec object MUST be `lzw`.
+
+## Configuration parameters
+
+None
+
+## Example
+
+For example, the array metadata below specifies that the array is compressed using the LZW method:
+
+```json
+{
+    "codecs": [{
+        "name": "lzw"
+    }]
+}
+```
+
+## Format and algorithm
+
+This is a `bytes -> bytes` codec.
+
+Encoding and decoding is performed using the algorithm defined in [Welch, "A Technique for High-Performance Data Compression," in Computer, vol. 17, no. 6, pp. 8-19, June 1984, doi: 10.1109/MC.1984.1659158](https://ieeexplore.ieee.org/document/1659158)
+
+## Change log
+
+No changes yet.
+
+## Current maintainers
+
+* [@cgohlke](https://github.com/cgohlke) in [imagecodecs](https://github.com/cgohlke/imagecodecs)
diff --git a/codecs/lzw/schema.json b/codecs/lzw/schema.json
new file mode 100644
index 0000000..f273c28
--- /dev/null
+++ b/codecs/lzw/schema.json
@@ -0,0 +1,16 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "oneOf": [
+    {
+      "type": "object",
+      "properties": {
+        "name": {
+          "const": "lzw"
+        }
+      },
+      "required": ["name"],
+      "additionalProperties": false
+    },
+    { "const": "lzw" }
+  ]
+}