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1 /*
2  * Copyright (c) 2016-2020 Arm Limited.
3  *
4  * SPDX-License-Identifier: MIT
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in all
14  * copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 #ifndef ARM_COMPUTE_NECUMULATIVEDISTRIBUTIONKERNEL_H
25 #define ARM_COMPUTE_NECUMULATIVEDISTRIBUTIONKERNEL_H
26 
27 #include "src/core/NEON/INEKernel.h"
28 
29 #include <cstdint>
30 
31 namespace arm_compute
32 {
33 class IDistribution1D;
34 class ILut;
35 class ITensor;
36 using IImage = ITensor;
37 
38 /** Interface for the cumulative distribution (cummulative summmation) calculation kernel.
39  *
40  * This kernel calculates the cumulative sum of a given distribution (meaning that each output element
41  * is the sum of all its previous elements including itself) and creates a lookup table with the normalized
42  * pixel intensities which is used for improve the constrast of the image.
43  */
44 class NECumulativeDistributionKernel : public INEKernel
45 {
46 public:
name()47     const char *name() const override
48     {
49         return "NECumulativeDistributionKernel";
50     }
51     /** Default constructor */
52     NECumulativeDistributionKernel();
53     /** Prevent instances of this class from being copied (As this class contains pointers) */
54     NECumulativeDistributionKernel(const NECumulativeDistributionKernel &) = delete;
55     /** Prevent instances of this class from being copied (As this class contains pointers) */
56     NECumulativeDistributionKernel &operator=(const NECumulativeDistributionKernel &) = delete;
57     /** Allow instances of this class to be moved */
58     NECumulativeDistributionKernel(NECumulativeDistributionKernel &&) = default;
59     /** Allow instances of this class to be moved */
60     NECumulativeDistributionKernel &operator=(NECumulativeDistributionKernel &&) = default;
61     /** Default destructor */
62     ~NECumulativeDistributionKernel() = default;
63     /** Set the input and output distribution.
64      *
65      * @param[in]  input          Input image. Data type supported: U8
66      * @param[in]  distribution   Unnormalized 256-bin distribution of the input image.
67      * @param[out] cumulative_sum Cummulative distribution (Summed histogram). Should be same size as @p distribution.
68      * @param[out] output         Equalization lookup table. Should consist of 256 entries of U8 elements.
69      */
70     void configure(const IImage *input, const IDistribution1D *distribution, IDistribution1D *cumulative_sum, ILut *output);
71 
72     // Inherited methods overridden:
73     void run(const Window &window, const ThreadInfo &info) override;
74     bool is_parallelisable() const override;
75 
76 private:
77     const IImage          *_input;          /**< Input image. */
78     const IDistribution1D *_distribution;   /**< Input histogram of the input image. */
79     IDistribution1D       *_cumulative_sum; /**< The cummulative distribution. */
80     ILut                  *_output;         /**< Output with the equalization lookup table. */
81 private:
82     static const uint32_t _histogram_size = 256; /**< Default histogram size of 256. */
83 };
84 } // namespace arm_compute
85 #endif /*ARM_COMPUTE_NECUMULATIVEDISTRIBUTIONKERNEL_H */
86