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ios/include/image/ImageOps.h

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+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#ifndef IMAGE_IMAGEOPS_H
+#define IMAGE_IMAGEOPS_H
+
+#include <image/LinearImage.h>
+
+#include <utils/compiler.h>
+
+#include <cstddef>
+#include <initializer_list>
+
+namespace image {
+
+// Concatenates images horizontally to create a filmstrip atlas, similar to numpy's hstack.
+UTILS_PUBLIC LinearImage horizontalStack(std::initializer_list<LinearImage> images);
+UTILS_PUBLIC LinearImage horizontalStack(LinearImage const* img, size_t count);
+
+// Concatenates images vertically to create a filmstrip atlas, similar to numpy's vstack.
+UTILS_PUBLIC LinearImage verticalStack(std::initializer_list<LinearImage> images);
+UTILS_PUBLIC LinearImage verticalStack(LinearImage const* img, size_t count);
+
+// Horizontally or vertically mirror the given image.
+UTILS_PUBLIC LinearImage horizontalFlip(const LinearImage& image);
+UTILS_PUBLIC LinearImage verticalFlip(const LinearImage& image);
+
+// Transforms normals (components live in [-1,+1]) into colors (components live in [0,+1]).
+UTILS_PUBLIC LinearImage vectorsToColors(const LinearImage& image);
+UTILS_PUBLIC LinearImage colorsToVectors(const LinearImage& image);
+
+// Creates a single-channel image by extracting the selected channel.
+UTILS_PUBLIC LinearImage extractChannel(const LinearImage& image, uint32_t channel);
+
+// Constructs a multi-channel image by copying data from a sequence of single-channel images.
+UTILS_PUBLIC LinearImage combineChannels(std::initializer_list<LinearImage> images);
+UTILS_PUBLIC LinearImage combineChannels(LinearImage const* img, size_t count);
+
+// Generates a new image with rows & columns swapped.
+UTILS_PUBLIC LinearImage transpose(const LinearImage& image);
+
+// Extracts pixels by specifying a crop window where (0,0) is the top-left corner of the image.
+// The boundary is specified as Left Top Right Bottom.
+UTILS_PUBLIC
+LinearImage cropRegion(const LinearImage& image, uint32_t l, uint32_t t, uint32_t r, uint32_t b);
+
+// Lexicographically compares two images, similar to memcmp.
+UTILS_PUBLIC int compare(const LinearImage& a, const LinearImage& b, float epsilon = 0.0f);
+
+// Sets all pixels in all channels to the given value.
+UTILS_PUBLIC void clearToValue(LinearImage& img, float value);
+
+// Called by the coordinate field generator to query if a pixel is within the region of interest.
+using PresenceCallback = bool(*)(const LinearImage& img, uint32_t col, uint32_t row, void* user);
+
+// Generates a two-channel field of non-normalized coordinates that indicate the nearest pixel
+// whose presence function returns true. This is the first step before generating a distance
+// field or generalized Voronoi map.
+UTILS_PUBLIC
+LinearImage computeCoordField(const LinearImage& src, PresenceCallback presence, void* user);
+
+// Generates a single-channel Euclidean distance field with positive values outside the region
+// of interest in the source image, and zero values inside. If sqrt is false, the computed
+// distances are squared. If signed distance (SDF) is desired, this function can be called a second
+// time using an inverted source field.
+UTILS_PUBLIC LinearImage edtFromCoordField(const LinearImage& coordField, bool sqrt);
+
+// Dereferences the given coordinate field. Useful for creating Voronoi diagrams or dilated images.
+UTILS_PUBLIC
+LinearImage voronoiFromCoordField(const LinearImage& coordField, const LinearImage& src);
+
+// Copies content of a source image into a target image. Requires width/height/channels to match.
+UTILS_PUBLIC void blitImage(LinearImage& target, const LinearImage& source);
+
+} // namespace image
+
+
+#endif /* IMAGE_LINEARIMAGE_H */