Add ImageProcessor library to ExecuTorch (pytorch#19967)

Differential Revision: D106898421

Pull Request resolved: pytorch#19967

Author: metascroy

CMakeLists.txt

@@ -864,6 +864,11 @@ if(EXECUTORCH_BUILD_EXTENSION_TENSOR)
   list(APPEND _executorch_extensions extension_tensor)
 endif()
 
+if(EXECUTORCH_BUILD_EXTENSION_IMAGE)
+  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/extension/image)
+  list(APPEND _executorch_extensions extension_image)
+endif()
+
 if(EXECUTORCH_BUILD_PTHREADPOOL AND EXECUTORCH_BUILD_CPUINFO)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/extension/threadpool)
 endif()

extension/image/BUCK

@@ -0,0 +1,5 @@
+load(":targets.bzl", "define_common_targets")
+
+oncall("executorch")
+
+define_common_targets()

extension/image/CMakeLists.txt

@@ -0,0 +1,45 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+cmake_minimum_required(VERSION 3.19)
+
+# stb_image_resize: lightweight header-only library used by the resize step in
+# image_processor.cpp.
+include(FetchContent)
+FetchContent_Declare(
+  stb
+  GIT_REPOSITORY https://github.com/nothings/stb.git
+  GIT_TAG f0569113c93ad095470c54bf34a17b36646bbbb5
+)
+FetchContent_MakeAvailable(stb)
+
+add_library(extension_image image_processor_common.cpp image_processor.cpp)
+
+target_include_directories(
+  extension_image PUBLIC ${_common_include_directories}
+)
+
+# stb_image_resize.h lives under deprecated/ in current stb. Private: only the
+# .cpp uses it, not the installed public headers.
+target_include_directories(
+  extension_image PRIVATE ${stb_SOURCE_DIR} ${stb_SOURCE_DIR}/deprecated
+)
+
+target_link_libraries(extension_image PUBLIC executorch_core extension_tensor)
+
+install(
+  TARGETS extension_image
+  EXPORT ExecuTorchTargets
+  DESTINATION ${CMAKE_INSTALL_LIBDIR}
+)
+
+install(FILES image_processor.h image_processor_config.h
+        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/executorch/extension/image
+)
+
+if(BUILD_TESTING)
+  add_subdirectory(test)
+endif()

extension/image/TARGETS

@@ -0,0 +1,5 @@
+load(":targets.bzl", "define_common_targets")
+
+oncall("executorch")
+
+define_common_targets()