芯启神枢，NPU 先行 · Add the Intel NPU OpenVINO backend

CHANGELOG.md

@@ -2,6 +2,19 @@
 
 This file records user-visible changes to `light-ocr`. Published artifact details and immutable hashes remain in [`docs/releases/`](docs/releases/).
 
+## [Unreleased]
+
+### Added
+
+- Added a source-level Intel NPU backend (`provider: "openvino"`) for Linux x64.
+  Builds configured with `LIGHT_OCR_OPENVINO_SDK_DIR` load the OpenVINO C
+  runtime at run time, run detection and 20-bucket recognition on the NPU, and
+  place `openvino` first in a qualification-only Auto policy
+  (`openvino → webgpu → cpu`); hosts without an NPU skip it with
+  `adapter_unavailable`. Published npm packages do not include OpenVINO yet, so
+  `provider: "openvino"` returns `unsupported_capability` there. See
+  [Intel NPU 加速技术方案](docs/intel-npu-acceleration.md).
+
 ## [0.5.8] - 2026-09-24
 
 ### Added

CMakeLists.txt

@@ -34,6 +34,10 @@ set(LIGHT_OCR_ORACLE_PYTHON "" CACHE FILEPATH "Pinned Python interpreter for par
 set(LIGHT_OCR_NODE_INCLUDE_DIR "" CACHE PATH "Directory containing node_api.h")
 set(LIGHT_OCR_NODE_LIBRARY "" CACHE FILEPATH "Windows Node import library")
 set(LIGHT_OCR_NODE_EXECUTABLE "" CACHE FILEPATH "Node.js executable used for adapter tests")
+set(LIGHT_OCR_OPENVINO_SDK_DIR "" CACHE PATH
+  "OpenVINO SDK root with include/openvino/c; enables the Intel NPU backend on Linux x64")
+set(LIGHT_OCR_OPENVINO_C_LIBRARY "" CACHE FILEPATH
+  "OpenVINO C runtime loaded by direct C++ callers; defaults to <SDK>/lib/libopenvino_c.so")
 
 if(LIGHT_OCR_ENABLE_SANITIZERS AND LIGHT_OCR_ENABLE_THREAD_SANITIZER)
   message(FATAL_ERROR "Address/Undefined sanitizers and ThreadSanitizer require separate builds")
@@ -138,6 +142,34 @@ if(LIGHT_OCR_HAS_WEBGPU)
   endif()
 endif()
 
+set(LIGHT_OCR_HAS_OPENVINO OFF)
+if(LIGHT_OCR_OPENVINO_SDK_DIR)
+  if(NOT (CMAKE_SYSTEM_NAME STREQUAL "Linux" AND
+          CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86_64|AMD64)$"))
+    message(FATAL_ERROR "The OpenVINO NPU backend currently targets Linux x64 only")
+  endif()
+  set(_light_ocr_openvino_include "${LIGHT_OCR_OPENVINO_SDK_DIR}/include")
+  if(NOT EXISTS "${_light_ocr_openvino_include}/openvino/c/openvino.h")
+    message(FATAL_ERROR
+      "LIGHT_OCR_OPENVINO_SDK_DIR has no include/openvino/c/openvino.h: ${LIGHT_OCR_OPENVINO_SDK_DIR}")
+  endif()
+  if(NOT LIGHT_OCR_OPENVINO_C_LIBRARY)
+    set(LIGHT_OCR_OPENVINO_C_LIBRARY "${LIGHT_OCR_OPENVINO_SDK_DIR}/lib/libopenvino_c.so")
+  endif()
+  if(NOT EXISTS "${LIGHT_OCR_OPENVINO_C_LIBRARY}")
+    message(FATAL_ERROR "OpenVINO C runtime not found: ${LIGHT_OCR_OPENVINO_C_LIBRARY}")
+  endif()
+  set(LIGHT_OCR_HAS_OPENVINO ON)
+  # Headers only: the runtime is loaded with dlopen so the library never
+  # becomes a link-time dependency of the Core or the Node addon.
+  target_sources(light_ocr_core PRIVATE src/inference/openvino/backend.cpp)
+  target_include_directories(light_ocr_core SYSTEM PRIVATE "${_light_ocr_openvino_include}")
+  target_compile_definitions(light_ocr_core PRIVATE
+    LIGHT_OCR_HAS_OPENVINO=1
+    LIGHT_OCR_OPENVINO_DEFAULT_LIBRARY="${LIGHT_OCR_OPENVINO_C_LIBRARY}")
+  target_link_libraries(light_ocr_core PRIVATE ${CMAKE_DL_LIBS})
+endif()
+
 if(MSVC)
   target_compile_options(light_ocr_core PRIVATE /W4 /WX /permissive- /EHsc /fp:strict)
 else()
@@ -210,6 +242,9 @@ if(LIGHT_OCR_BUILD_TESTS)
     target_compile_definitions(light_ocr_unit_tests PRIVATE
       LIGHT_OCR_WEBGPU_QUALIFICATION_BUILD=1)
   endif()
+  if(LIGHT_OCR_HAS_OPENVINO)
+    target_compile_definitions(light_ocr_unit_tests PRIVATE LIGHT_OCR_HAS_OPENVINO=1)
+  endif()
   light_ocr_stage_onnxruntime(light_ocr_unit_tests)
   add_test(NAME light_ocr_unit_tests COMMAND light_ocr_unit_tests)
 

bindings/node/src/addon.cpp

@@ -499,9 +499,10 @@ ExecutionProvider parse_execution_provider(napi_env env, napi_value value) {
   if (provider == "cpu") return ExecutionProvider::cpu;
   if (provider == "apple") return ExecutionProvider::apple;
   if (provider == "webgpu") return ExecutionProvider::webgpu;
+  if (provider == "openvino") return ExecutionProvider::openvino;
   throw AddonFailure(
       "invalid_argument",
-      "execution.provider must be auto, cpu, apple, or webgpu");
+      "execution.provider must be auto, cpu, apple, webgpu, or openvino");
 }
 
 SessionFallback parse_session_fallback(napi_env env, napi_value value) {
@@ -1621,6 +1622,7 @@ const char* execution_provider_string(ExecutionProvider provider) {
     case ExecutionProvider::cpu: return "cpu";
     case ExecutionProvider::apple: return "apple";
     case ExecutionProvider::webgpu: return "webgpu";
+    case ExecutionProvider::openvino: return "openvino";
   }
   return "auto";
 }

docs/cli-design.md

@@ -114,7 +114,7 @@ light-ocr detect image.png --provider webgpu
 | `--format` | json \| jsonl \| text | 默认 `json` |
 | `--region` | `x,y,w,h` | pageSpace 轴对齐矩形，整数像素；详见 §7 |
 | `--no-exif` | flag | 关闭默认 EXIF orientation 修正；详见 §6 |
-| `--provider` | auto \| cpu \| apple \| webgpu | 映射 `execution.provider` |
+| `--provider` | auto \| cpu \| apple \| webgpu \| openvino | 映射 `execution.provider`；`openvino` 仅在包含 OpenVINO NPU runtime 的构建中可用 |
 | `--schema-version` | 1 | 请求精确输出 schema；不支持则稳定失败 |
 
 `--help` 第二层（高级）：