1 /* This file is part of the Pangolin Project.
2 * http://github.com/stevenlovegrove/Pangolin
3 *
4 * Copyright (c) 2013 Steven Lovegrove
5 *
6 * Permission is hereby granted, free of charge, to any person
7 * obtaining a copy of this software and associated documentation
8 * files (the "Software"), to deal in the Software without
9 * restriction, including without limitation the rights to use,
10 * copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following
13 * conditions:
14 *
15 * The above copyright notice and this permission notice shall be
16 * included in all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
20 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
22 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
23 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25 * OTHER DEALINGS IN THE SOFTWARE.
26 */
27
28 #pragma once
29
30 #include <limits>
31 #include <utility>
32
33 #include <pangolin/image/image.h>
34 #include <pangolin/plot/range.h>
35 #include <pangolin/gl/gl.h>
36 #include <pangolin/gl/glpixformat.h>
37
38 namespace pangolin
39 {
40
41 namespace internal
42 {
43
44 template <typename T>
GetMinMax(const Image<T> & img,size_t channels)45 std::pair<float, float> GetMinMax(const Image<T>& img, size_t channels)
46 {
47 const size_t max_channels = 3;
48 const size_t colour_channels = std::min(channels, max_channels);
49 std::pair<float, float> chan_mm[max_channels];
50 for(size_t c = 0; c < max_channels; ++c)
51 {
52 chan_mm[c].first = +std::numeric_limits<float>::max();
53 chan_mm[c].second = -std::numeric_limits<float>::max();
54 }
55
56 for(size_t y = 0; y < img.h; ++y)
57 {
58 T* pix = (T*)((char*)img.ptr + y * img.pitch);
59 for(size_t x = 0; x < img.w; ++x)
60 {
61 for(size_t c = 0; c < colour_channels; ++c)
62 {
63 if(pix[c] < chan_mm[c].first)
64 chan_mm[c].first = (float)pix[c];
65 if(pix[c] > chan_mm[c].second)
66 chan_mm[c].second = (float)pix[c];
67 }
68
69 pix += channels;
70 }
71 }
72
73 // Find min / max of all channels, ignoring 4th alpha channel
74 std::pair<float, float> mm = chan_mm[0];
75 for(size_t c = 1; c < colour_channels; ++c)
76 {
77 mm.first = std::min(mm.first, chan_mm[c].first);
78 mm.second = std::max(mm.second, chan_mm[c].second);
79 }
80
81 return mm;
82 }
83
84 template<typename T>
GetImageRoi(pangolin::Image<T> img,size_t channels,const pangolin::XYRangei & roi)85 pangolin::Image<T> GetImageRoi( pangolin::Image<T> img, size_t channels, const pangolin::XYRangei& roi )
86 {
87 return pangolin::Image<T>(
88 img.RowPtr(std::min(roi.y.min,roi.y.max)) + channels*std::min(roi.x.min,roi.x.max),
89 roi.x.AbsSize(), roi.y.AbsSize(),
90 img.pitch
91 );
92 }
93
94 template<typename T>
GetOffsetScale(const pangolin::Image<T> & img,size_t channels,float type_max,float format_max)95 std::pair<float,float> GetOffsetScale(const pangolin::Image<T>& img, size_t channels, float type_max, float format_max)
96 {
97 // Find min / max of all channels, ignoring 4th alpha channel
98 const std::pair<float,float> mm = internal::GetMinMax<T>(img,channels);
99 const float type_scale = format_max / type_max;
100 const float offset = -type_scale* mm.first;
101 const float scale = type_max / (mm.second - mm.first);
102 return std::pair<float,float>(offset, scale);
103 }
104
105 template<typename T>
GetScaleOnly(const pangolin::Image<T> & img,size_t channels,float type_max,float)106 float GetScaleOnly(const pangolin::Image<T>& img, size_t channels, float type_max, float /*format_max*/)
107 {
108 // Find min / max of all channels, ignoring 4th alpha channel
109 const std::pair<float,float> mm = internal::GetMinMax<T>(img,channels);
110 const float scale = type_max / mm.second;
111 return scale;
112 }
113
114 } // internal
115
GetMinMax(const Image<unsigned char> & img,XYRangei iroi,const GlPixFormat & glfmt)116 inline std::pair<float, float> GetMinMax(
117 const Image<unsigned char>& img,
118 XYRangei iroi, const GlPixFormat& glfmt
119 ) {
120 using namespace internal;
121
122 iroi.Clamp(0, (int)img.w - 1, 0, (int)img.h - 1);
123
124 const size_t num_channels = pangolin::GlFormatChannels(glfmt.glformat);
125
126 if(glfmt.gltype == GL_UNSIGNED_BYTE) {
127 return GetMinMax(GetImageRoi(img.template UnsafeReinterpret<unsigned char>(), num_channels, iroi), num_channels);
128 } else if(glfmt.gltype == GL_UNSIGNED_SHORT) {
129 return GetMinMax(GetImageRoi(img.template UnsafeReinterpret<unsigned short>(), num_channels, iroi), num_channels);
130 } else if(glfmt.gltype == GL_FLOAT) {
131 return GetMinMax(GetImageRoi(img.template UnsafeReinterpret<float>(), num_channels, iroi), num_channels);
132 } else if(glfmt.gltype == GL_DOUBLE) {
133 return GetMinMax(GetImageRoi(img.template UnsafeReinterpret<double>(), num_channels, iroi), num_channels);
134 } else {
135 return std::pair<float, float>(std::numeric_limits<float>::max(), std::numeric_limits<float>::lowest());
136 }
137 }
138
GetOffsetScale(const pangolin::Image<unsigned char> & img,pangolin::XYRangei iroi,const pangolin::GlPixFormat & glfmt)139 inline std::pair<float,float> GetOffsetScale(
140 const pangolin::Image<unsigned char>& img,
141 pangolin::XYRangei iroi, const pangolin::GlPixFormat& glfmt
142 ) {
143 using namespace internal;
144
145 iroi.Clamp(0, (int)img.w-1, 0, (int)img.h-1 );
146
147 const size_t num_channels = pangolin::GlFormatChannels(glfmt.glformat);
148
149 if(glfmt.gltype == GL_UNSIGNED_BYTE) {
150 return GetOffsetScale(GetImageRoi(img.template UnsafeReinterpret<unsigned char>(), num_channels, iroi), num_channels, 255.0f, 1.0f);
151 }else if(glfmt.gltype == GL_UNSIGNED_SHORT) {
152 return GetOffsetScale(GetImageRoi(img.template UnsafeReinterpret<unsigned short>(), num_channels, iroi), num_channels, 65535.0f, 1.0f);
153 }else if(glfmt.gltype == GL_FLOAT) {
154 return GetOffsetScale(GetImageRoi(img.template UnsafeReinterpret<float>(), num_channels, iroi), num_channels, 1.0f, 1.0f);
155 }else if(glfmt.gltype == GL_DOUBLE) {
156 return GetOffsetScale(GetImageRoi(img.template UnsafeReinterpret<double>(), num_channels, iroi), num_channels, 1.0f, 1.0f);
157 }else{
158 return std::pair<float,float>(0.0f, 1.0f);
159 }
160 }
161
GetScaleOnly(const pangolin::Image<unsigned char> & img,pangolin::XYRangei iroi,const pangolin::GlPixFormat & glfmt)162 inline float GetScaleOnly(
163 const pangolin::Image<unsigned char>& img,
164 pangolin::XYRangei iroi, const pangolin::GlPixFormat& glfmt
165 ) {
166 using namespace internal;
167
168 iroi.Clamp(0, (int)img.w-1, 0, (int)img.h-1 );
169
170 const size_t num_channels = pangolin::GlFormatChannels(glfmt.glformat);
171
172 if(glfmt.gltype == GL_UNSIGNED_BYTE) {
173 return GetScaleOnly(GetImageRoi(img.template UnsafeReinterpret<unsigned char>(), num_channels, iroi), num_channels, 255.0f, 1.0f);
174 }else if(glfmt.gltype == GL_UNSIGNED_SHORT) {
175 return GetScaleOnly(GetImageRoi(img.template UnsafeReinterpret<unsigned short>(), num_channels, iroi), num_channels, 65535.0f, 1.0f);
176 }else if(glfmt.gltype == GL_FLOAT) {
177 return GetScaleOnly(GetImageRoi(img.template UnsafeReinterpret<float>(), num_channels, iroi), num_channels, 1.0f, 1.0f);
178 }else if(glfmt.gltype == GL_DOUBLE) {
179 return GetScaleOnly(GetImageRoi(img.template UnsafeReinterpret<double>(), num_channels, iroi), num_channels, 1.0f, 1.0f);
180 }else{
181 return 1.0f;
182 }
183 }
184
185 }
186