1# OH_Pixelmap_HdrGainmapMetadata
2
3
4## Overview
5
6The OH_Pixelmap_HdrGainmapMetadata struct describes the gain map metadata values available for the key **HDR_GAINMAP_METADATA**. For details, see ISO 21496-1.
7
8**Since**: 12
9
10**Related module**: [Image_NativeModule](_image___native_module.md)
11
12
13## Summary
14
15
16### Member Variables
17
18| Name| Description|
19| -------- | -------- |
20| uint16_t [writerVersion](#writerversion) | Version used by the metadata editor. |
21| uint16_t [miniVersion](#miniversion) | Minimum version that needs to be understood for metadata parsing. |
22| uint8_t [gainmapChannelNum](#gainmapchannelnum) | Number of color channels of the gain map. When the value is 3, the metadata values of the RGB channels are different. When the value is 1, the metadata values of the RGB channels are the same. |
23| bool [useBaseColorFlag](#usebasecolorflag) | Whether to use the color space of the base graphic. For details, see ISO 21496-1. |
24| float [baseHeadroom](#baseheadroom) | Headroom of the base graphic, which means the additional brightness that can be added to the base graphic. For details, see ISO 21496-1. |
25| float [alternateHeadroom](#alternateheadroom) | Headroom of the alternate graphic. For details, see ISO 21496-1. |
26| float [gainmapMax](#gainmapmax)[3] | Maximum value of the gain map. For details, see ISO 21496-1. |
27| float [gainmapMin](#gainmapmin)[3] | Minimum value of the gain map. For details, see ISO 21496-1. |
28| float [gamma](#gamma)[3] | Gamma. For details, see ISO 21496-1. |
29| float [baselineOffset](#baselineoffset)[3] | Offset of the base graphic. For details, see ISO 21496-1. |
30| float [alternateOffset](#alternateoffset)[3] | Offset of the alternative graphic that can be extracted. For details, see ISO 21496-1. |
31
32
33## Member Variable Description
34
35
36### alternateHeadroom
37
38```
39float OH_Pixelmap_HdrGainmapMetadata::alternateHeadroom
40```
41
42**Description**
43
44Headroom of the alternate graphic. For details, see ISO 21496-1.
45
46
47### alternateOffset
48
49```
50float OH_Pixelmap_HdrGainmapMetadata::alternateOffset[3]
51```
52
53**Description**
54
55Offset of the alternative graphic that can be extracted. For details, see ISO 21496-1.
56
57
58### baseHeadroom
59
60```
61float OH_Pixelmap_HdrGainmapMetadata::baseHeadroom
62```
63
64**Description**
65
66Headroom of the base graphic, which means the additional brightness that can be added to the base graphic. For details, see ISO 21496-1.
67
68
69### baselineOffset
70
71```
72float OH_Pixelmap_HdrGainmapMetadata::baselineOffset[3]
73```
74
75**Description**
76
77Offset of the base graphic. For details, see ISO 21496-1.
78
79
80### gainmapChannelNum
81
82```
83uint8_t OH_Pixelmap_HdrGainmapMetadata::gainmapChannelNum
84```
85
86**Description**
87
88Number of color channels of the gain map. When the value is 3, the metadata values of the RGB channels are different. When the value is 1, the metadata values of the RGB channels are the same.
89
90
91### gainmapMax
92
93```
94float OH_Pixelmap_HdrGainmapMetadata::gainmapMax[3]
95```
96
97**Description**
98
99Maximum value of the gain map. For details, see ISO 21496-1.
100
101
102### gainmapMin
103
104```
105float OH_Pixelmap_HdrGainmapMetadata::gainmapMin[3]
106```
107
108**Description**
109
110Minimum value of the gain map. For details, see ISO 21496-1.
111
112
113### gamma
114
115```
116float OH_Pixelmap_HdrGainmapMetadata::gamma[3]
117```
118
119**Description**
120
121Gamma. For details, see ISO 21496-1.
122
123
124### miniVersion
125
126```
127uint16_t OH_Pixelmap_HdrGainmapMetadata::miniVersion
128```
129
130**Description**
131
132Minimum version that needs to be understood for metadata parsing.
133
134
135### useBaseColorFlag
136
137```
138bool OH_Pixelmap_HdrGainmapMetadata::useBaseColorFlag
139```
140
141**Description**
142
143Whether to use the color space of the base graphic. For details, see ISO 21496-1.
144
145
146### writerVersion
147
148```
149uint16_t OH_Pixelmap_HdrGainmapMetadata::writerVersion
150```
151
152**Description**
153
154Version used by the metadata editor.
155