1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
//
// Copyright © 2017 Arm Ltd. All rights reserved.
// SPDX-License-Identifier: MIT
//
#include "MnistDatabase.hpp"
#include <armnn/Logging.hpp>
#include <fstream>
#include <vector>
constexpr int g_kMnistImageByteSize = 28 * 28;
void EndianSwap(unsigned int &x)
{
x = (x >> 24) | ((x << 8) & 0x00FF0000) | ((x >> 8) & 0x0000FF00) | (x << 24);
}
MnistDatabase::MnistDatabase(const std::string& binaryFileDirectory, bool scaleValues)
: m_BinaryDirectory(binaryFileDirectory)
, m_ScaleValues(scaleValues)
{
}
std::unique_ptr<MnistDatabase::TTestCaseData> MnistDatabase::GetTestCaseData(unsigned int testCaseId)
{
std::vector<unsigned char> I(g_kMnistImageByteSize);
unsigned int label = 0;
std::string imagePath = m_BinaryDirectory + std::string("t10k-images.idx3-ubyte");
std::string labelPath = m_BinaryDirectory + std::string("t10k-labels.idx1-ubyte");
std::ifstream imageStream(imagePath, std::ios::binary);
std::ifstream labelStream(labelPath, std::ios::binary);
if (!imageStream.is_open())
{
ARMNN_LOG(fatal) << "Failed to load " << imagePath;
return nullptr;
}
if (!labelStream.is_open())
{
ARMNN_LOG(fatal) << "Failed to load " << imagePath;
return nullptr;
}
unsigned int magic, num, row, col;
// Checks the files have the correct header.
imageStream.read(reinterpret_cast<char*>(&magic), sizeof(magic));
if (magic != 0x03080000)
{
ARMNN_LOG(fatal) << "Failed to read " << imagePath;
return nullptr;
}
labelStream.read(reinterpret_cast<char*>(&magic), sizeof(magic));
if (magic != 0x01080000)
{
ARMNN_LOG(fatal) << "Failed to read " << labelPath;
return nullptr;
}
// Endian swaps the image and label file - all the integers in the files are stored in MSB first(high endian)
// format, hence it needs to flip the bytes of the header if using it on Intel processors or low-endian machines
labelStream.read(reinterpret_cast<char*>(&num), sizeof(num));
imageStream.read(reinterpret_cast<char*>(&num), sizeof(num));
EndianSwap(num);
imageStream.read(reinterpret_cast<char*>(&row), sizeof(row));
EndianSwap(row);
imageStream.read(reinterpret_cast<char*>(&col), sizeof(col));
EndianSwap(col);
// Reads image and label into memory.
imageStream.seekg(testCaseId * g_kMnistImageByteSize, std::ios_base::cur);
imageStream.read(reinterpret_cast<char*>(&I[0]), g_kMnistImageByteSize);
labelStream.seekg(testCaseId, std::ios_base::cur);
labelStream.read(reinterpret_cast<char*>(&label), 1);
if (!imageStream.good())
{
ARMNN_LOG(fatal) << "Failed to read " << imagePath;
return nullptr;
}
if (!labelStream.good())
{
ARMNN_LOG(fatal) << "Failed to read " << labelPath;
return nullptr;
}
std::vector<float> inputImageData;
inputImageData.resize(g_kMnistImageByteSize);
for (unsigned int i = 0; i < col * row; ++i)
{
// Static_cast of unsigned char is safe with float
inputImageData[i] = static_cast<float>(I[i]);
if(m_ScaleValues)
{
inputImageData[i] /= 255.0f;
}
}
return std::make_unique<TTestCaseData>(label, std::move(inputImageData));
}
|
