MLECO-2082: Adding visual wake word use case
MLECO-2083: Refactoring img_class and visual wake word

*Added source files for visual wake word
*Added tests
*Added docs
*Added new images for visual wake word demo
*Refactored common functions in img_class, visual wake word and other usecases

Change-Id: Ibd25854e19a5517f940a8d3086a5d4835fab89e9
Signed-off-by: Éanna Ó Catháin <eanna.ocathain@arm.com>
diff --git a/source/use_case/vww/usecase.cmake b/source/use_case/vww/usecase.cmake
new file mode 100644
index 0000000..9a732b7
--- /dev/null
+++ b/source/use_case/vww/usecase.cmake
@@ -0,0 +1,62 @@
+#  Copyright (c) 2021 Arm Limited. All rights reserved.
+#  SPDX-License-Identifier: Apache-2.0
+# 
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+# 
+#      http://www.apache.org/licenses/LICENSE-2.0
+# 
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+ 
+
+USER_OPTION(${use_case}_FILE_PATH "Directory with custom image files, or path to a single image file, to use in the evaluation application"
+    ${CMAKE_CURRENT_SOURCE_DIR}/resources/${use_case}/samples/
+    PATH_OR_FILE)
+
+USER_OPTION(${use_case}_IMAGE_SIZE "Square image size in pixels. Images will be resized to this size."
+    128
+    STRING)
+
+USER_OPTION(${use_case}_LABELS_TXT_FILE "Labels' txt file for the chosen model"
+    ${CMAKE_CURRENT_SOURCE_DIR}/resources/${use_case}/labels/visual_wake_word_labels.txt
+    FILEPATH)
+
+USER_OPTION(${use_case}_ACTIVATION_BUF_SZ "Activation buffer size for the chosen model"
+    0x00200000
+    STRING)
+
+if (ETHOS_U55_ENABLED)
+    set(DEFAULT_MODEL_PATH      ${DEFAULT_MODEL_DIR}/vww4_128_128_INT8_vela_H128.tflite)
+else()
+    set(DEFAULT_MODEL_PATH      ${DEFAULT_MODEL_DIR}/vww4_128_128_INT8.tflite)
+endif()
+
+USER_OPTION(${use_case}_MODEL_TFLITE_PATH "NN models file to be used in the evaluation application. Model files must be in tflite format."
+    ${DEFAULT_MODEL_PATH}
+    FILEPATH)
+
+# Generate model file
+generate_tflite_code(
+    MODEL_PATH ${${use_case}_MODEL_TFLITE_PATH}
+    DESTINATION ${SRC_GEN_DIR}
+)
+
+# Generate labels file
+set(${use_case}_LABELS_CPP_FILE Labels)
+generate_labels_code(
+    INPUT           "${${use_case}_LABELS_TXT_FILE}"
+    DESTINATION_SRC ${SRC_GEN_DIR}
+    DESTINATION_HDR ${INC_GEN_DIR}
+    OUTPUT_FILENAME "${${use_case}_LABELS_CPP_FILE}"
+)
+
+# Generate input files
+generate_images_code("${${use_case}_FILE_PATH}"
+                     ${SRC_GEN_DIR}
+                     ${INC_GEN_DIR}
+                     "${${use_case}_IMAGE_SIZE}")