diff --git a/CHANGES.md b/CHANGES.md
index cb0f7228e0..0b736ed917 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,21 @@
-Release 2.3.19 (1 Sep?? 2022) -- compared to 2.3.18
+Release 2.3.19 (1 Sep 2022) -- compared to 2.3.18
 ---------------------------------------------------
+* idiff: `--allowfailures` allows the specified number of pixels to differ by
+  any amount, and still consider the images to compare successfully. #3455
+* idiff: `--failrelative` and `--warnrelative` allows the failure and warning
+  threshold to use a symmetric mean relative error (rather than the absolute
+  error implied by the existing `--fail` and `--warn` arguments). #3508
+* A new flavor of `ImageBufAlgo::compare()` allows relative as well as
+  absolute error thresholds. #3508
+* Build: Fixes for ffmpeg 5.1 detection. #3516
+* Build: suppress incorrect warnings for gcc 12. #3524
+* CI: New test on MacOS 12, remove test on MacOS 10.15 (GitHub Actions is
+  imminently removing MacOS 10.15). #3528
+* oiiotool, maketx, iinfo, igrep, and iv now all take a `--version` command
+  line argument, which just prints the OIIO version and exits. #3534
+* `OIIO::getattribute("version")` now retrieves the version string. #3534
+* Developer goodies: `ArgParse::add_version(str)` tells ArgParse the version
+  string, which will automatically add an option `--version`. #3534
 
 Release 2.3.18 (1 Aug 2022) -- compared to 2.3.17
 ---------------------------------------------------
diff --git a/INSTALL.md b/INSTALL.md
index 0a6b232d58..5a38589644 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -19,13 +19,13 @@ NEW or CHANGED MINIMUM dependencies since the last major release are **bold**.
        CMake configuration flag: `-DCMAKE_CXX_STANDARD=17`, etc.
  * Compilers: **gcc 6.1 - 11.2**, **clang 3.4 - 14**, **MSVS 2017 - 2019**,
    **Intel icc 17+**, **Intel OneAPI C++ compiler 2022+**.
- * CMake >= 3.12 (tested through 3.23)
+ * CMake >= 3.12 (tested through 3.24)
  * OpenEXR/Imath >= 2.0 (recommended: 2.4 or higher; tested through 3.1)
  * libTIFF >= 3.9 (recommended: 4.0+; tested through 4.4)
  * libjpeg >= 8, or libjpeg-turbo >= 1.1 (tested through jpeg9d and jpeg-turbo
    2.1)
- * Boost >= 1.53 (recommended: at least 1.66; tested through 1.78)
- * [fmtlib](https://github.com/fmtlib/fmt) >= 6.1.2 (tested through 9.0). If
+ * Boost >= 1.53 (recommended: at least 1.66; tested through 1.80)
+ * [fmtlib](https://github.com/fmtlib/fmt) >= 6.1.2 (tested through 9.1). If
    not found at build time, this will be automatically downloaded unless the
    build sets `-DBUILD_MISSING_FMT=OFF`.
 
@@ -35,7 +35,7 @@ NEW or CHANGED MINIMUM dependencies since the last major release are **bold**.
      * Qt >= 5.6 (tested through 5.15)
      * OpenGL
  * If you are building the Python bindings or running the testsuite:
-     * Python >= 2.7 (tested against 2.7, 3.7, 3.8, 3.9)
+     * Python >= 2.7 (tested against 2.7, 3.7, 3.8, 3.9, 3.10)
      * pybind11 >= 2.4.2 (Tested through 2.10. Note that pybind11 v2.10+ does
        not support Python < 3.6.)
      * NumPy
@@ -44,7 +44,7 @@ NEW or CHANGED MINIMUM dependencies since the last major release are **bold**.
        ACES support and much better recognition of camera metadata; if
        building with C++17 or higher, LibRaw >= 0.20 is necessary)
  * If you want support for a wide variety of video formats:
-     * **ffmpeg >= 3.0** (tested through 5.0)
+     * **ffmpeg >= 3.0** (tested through 5.1)
  * If you want support for jpeg 2000 images:
      * **OpenJpeg >= 2.0** (tested through 2.4; we recommend 2.4 or higher
        for multithreading support)
diff --git a/src/doc/idiff.rst b/src/doc/idiff.rst
index 275396f3dd..41cf4b9b15 100644
--- a/src/doc/idiff.rst
+++ b/src/doc/idiff.rst
@@ -168,6 +168,13 @@ Thresholds and comparison options
     than 0% (any) pixels differ by more than 0.00001 (1e-6), and *H* is
     infinite.
 
+.. describe:: --allowfailures N
+
+    Allows up to *N* pixels to differ by any amount, and still consider it
+    a matching image.
+
+    This option was added in OIIO 2.3.19.
+
 .. describe:: -p
 
     Does an additional test on the images to attempt to see if they are