1# Image 2 3 4Provides APIs for obtaining pixel map data and information. 5 6To use the APIs in this file, **libpixelmap_ndk.z.so** is required. 7 8@Syscap SystemCapability.Multimedia.Image 9 10**Since** 11 12 138 14 15 16## Summary 17 18 19### Files 20 21| Name| Description| 22| -------- | -------- | 23| [image_pixel_map_napi.h](image__pixel__map__napi_8h.md) | Declares the APIs that can lock, access, and unlock a pixel map.<br>File to include: <multimedia/image_framework/image_pixel_map_napi.h> | 24 25 26### Structs 27 28| Name| Description| 29| -------- | -------- | 30| [OhosPixelMapInfo](_ohos_pixel_map_info.md) | Defines the pixel map information.| 31 32 33### Types 34 35| Name| Description| 36| -------- | -------- | 37| { OHOS_IMAGE_RESULT_SUCCESS = 0, OHOS_IMAGE_RESULT_BAD_PARAMETER = -1 } | Enumerates the error codes returned by the functions.| 38| { OHOS_PIXEL_MAP_FORMAT_NONE = 0, OHOS_PIXEL_MAP_FORMAT_RGBA_8888 = 3, OHOS_PIXEL_MAP_FORMAT_RGB_565 = 2 } | Enumerates the pixel formats.| 39 40 41### Functions 42 43| Name| Description| 44| -------- | -------- | 45| [OH_GetImageInfo](#oh_getimageinfo) (napi_env env, napi_value value, [OhosPixelMapInfo](_ohos_pixel_map_info.md) \*info) | Obtains the **PixelMap** information and stores the information to the [OhosPixelMapInfo](_ohos_pixel_map_info.md) struct.| 46| [OH_AccessPixels](#oh_accesspixels) (napi_env env, napi_value value, void \*\*addrPtr) | Obtains the memory address of a **PixelMap** object and locks the memory.| 47| [OH_UnAccessPixels](#oh_unaccesspixels) (napi_env env, napi_value value) | Unlocks the memory of a **PixelMap** object. This function is used with [OH_AccessPixels](#oh_accesspixels) in pairs.| 48 49 50## Type Description 51 52 53### anonymous enum 54 55 56``` 57anonymous enum 58``` 59**Description** 60 61Enumerates the error codes returned by the functions. 62 63| Value| Description| 64| -------- | -------- | 65| OHOS_IMAGE_RESULT_SUCCESS| Operation success.| 66| OHOS_IMAGE_RESULT_BAD_PARAMETER| Invalid value.| 67 68**Since** 69 708 71 72### anonymous enum 73 74 75``` 76anonymous enum 77``` 78**Description** 79 80Enumerates the pixel formats. 81 82| Value| Description| 83| -------- | -------- | 84| OHOS_PIXEL_MAP_FORMAT_NONE| Unknown format.| 85| OHOS_PIXEL_MAP_FORMAT_RGBA_8888| 32-bit RGBA, with 8 bits each for R (red), G (green), B (blue), and A (alpha). The data is stored from the most significant bit to the least significant bit.| 86| OHOS_PIXEL_MAP_FORMAT_RGB_565| 16-bit RGB, with 5, 6, and 5 bits for R, G, and B, respectively. The storage sequence is from the most significant bit to the least significant bit.| 87 88**Since** 89 908 91 92## anonymous enum 93 94 95### OH_AccessPixels() 96 97 98``` 99int32_t OH_AccessPixels (napi_env env, napi_value value, void ** addrPtr ) 100``` 101**Description** 102 103Obtains the memory address of a **PixelMap** object and locks the memory. 104 105After the function is executed successfully, **\*addrPtr** is the address of the memory to be accessed. After the access operation is complete, you must use [OH_UnAccessPixels](#oh_unaccesspixels) to unlock the memory. Otherwise, the resources in the memory cannot be released. After the memory is unlocked, its address cannot be accessed or operated. 106 107**Parameters** 108 109| Name| Description| 110| -------- | -------- | 111| env | Indicates the NAPI environment pointer.| 112| value | Indicates the **PixelMap** object at the application layer.| 113| addrPtr | Indicates the double pointer to the memory address.| 114 115**See** 116 117UnAccessPixels 118 119**Returns** 120 121Returns **OHOS_IMAGE_RESULT_SUCCESS** if the operation is successful; returns an error code otherwise. 122 123**Since** 1248 125 126 127### OH_GetImageInfo() 128 129 130``` 131struct OhosPixelMapCreateOps OH_GetImageInfo (napi_env env, napi_value value, OhosPixelMapInfo * info ) 132``` 133**Description** 134 135Obtains the **PixelMap** information and stores the information to the [OhosPixelMapInfo](_ohos_pixel_map_info.md) struct. 136 137**Parameters** 138 139| Name| Description| 140| -------- | -------- | 141| env | Indicates the NAPI environment pointer.| 142| value | Indicates the **PixelMap** object at the application layer.| 143| info | Indicates the pointer to the object that stores the information obtained. For details, see [OhosPixelMapInfo](_ohos_pixel_map_info.md).| 144 145**Returns** 146 147Returns **0** if the information is obtained and stored successfully; returns an error code otherwise. 148 149**See** 150 151[OhosPixelMapInfo](_ohos_pixel_map_info.md) 152 153**Since** 154 1558 156 157### OH_UnAccessPixels() 158 159 160``` 161int32_t OH_UnAccessPixels (napi_env env, napi_value value ) 162``` 163**Description** 164 165Unlocks the memory of a **PixelMap** object. This function is used with [OH_AccessPixels](#oh_accesspixels) in pairs. 166 167**Parameters** 168 169| Name| Description| 170| -------- | -------- | 171| env | Indicates the NAPI environment pointer.| 172| value | Indicates the **PixelMap** object at the application layer.| 173 174**Returns** 175 176Returns **OHOS_IMAGE_RESULT_SUCCESS** if the operation is successful; returns an error code otherwise. 177 178**See** 179 180AccessPixels 181 182**Since** 183 1848 185 186