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en/application-dev/reference/apis/js-apis-image.md
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# Image Processing
> **NOTE**<br/>
> The initial APIs of this module are supported since API version 6. Newly added APIs will be marked with a superscript to indicate their earliest API version.
> **NOTE**
>
> API version 9 is a canary release for trial use. The APIs of this version may be unstable.
> The initial APIs of this module are supported since API version 6. Newly added APIs will be marked with a superscript to indicate their earliest API version.
## Modules to Import
```
```js
import image from '@ohos.multimedia.image';
```
......@@ -22,8 +21,8 @@ Creates a **PixelMap** object. This API uses a promise to return the result.
| Name | Type | Mandatory| Description |
| ------- | ------------------------------------------------ | ---- | ------------------------------------------------------------ |
| colors | ArrayBuffer | Yes | Color array. |
| options | [InitializetionOptions](#initializationoptions8) | Yes | Pixel properties, including the alpha type, size, scale mode, pixel format, and editable.|
| colors | ArrayBuffer | Yes | Color array in BGRA_8888 format. |
| options | [InitializationOptions](#initializationoptions8) | Yes | Pixel properties, including the alpha type, size, scale mode, pixel format, and editable.|
**Return value**
......@@ -34,9 +33,11 @@ Creates a **PixelMap** object. This API uses a promise to return the result.
**Example**
```js
image.createPixelMap(Color, opts)
.then((pixelmap) => {
})
const color = new ArrayBuffer(96);
let opts = { editable: true, pixelFormat: 3, size: { height: 4, width: 6 } }
image.createPixelMap(color, opts)
.then((pixelmap) => {
})
```
## image.createPixelMap<sup>8+</sup>
......@@ -51,15 +52,17 @@ Creates a **PixelMap** object. This API uses an asynchronous callback to return
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------------------ | ---- | -------------------------- |
| colors | ArrayBuffer | Yes | Color array. |
| options | [InitializetionOptions](#initializationoptions8) | Yes | Pixel properties. |
| colors | ArrayBuffer | Yes | Color array in BGRA_8888 format. |
| options | [InitializationOptions](#initializationoptions8) | Yes | Pixel properties. |
| callback | AsyncCallback\<[PixelMap](#pixelmap7)> | Yes | Callback used to return the **PixelMap** object.|
**Example**
```js
image.createPixelMap(Color, opts, (pixelmap) => {
})
const color = new ArrayBuffer(96);
let opts = { editable: true, pixelFormat: 3, size: { height: 4, width: 6 } }
image.createPixelMap(color, opts, (pixelmap) => {
})
```
## PixelMap<sup>7+</sup>
......@@ -68,9 +71,11 @@ Provides APIs to read or write image pixel map data and obtain image pixel map i
### Attributes
| Name | Type | Readable| Writable| Description |
| ----------------------- | ------- | ---- | ---- | ------------------------------------------------------------ |
| isEditable<sup>7+</sup> | boolean | Yes | No | Whether the image pixel map is editable.<br>**System capability**: SystemCapability.Multimedia.Image|
**System capability**: SystemCapability.Multimedia.Image
| Name | Type | Readable| Writable| Description |
| ----------------------- | ------- | ---- | ---- | -------------------------- |
| isEditable<sup>7+</sup> | boolean | Yes | No | Whether the image pixel map is editable.|
### readPixelsToBuffer<sup>7+</sup>
......@@ -95,11 +100,11 @@ Reads image pixel map data and writes the data to an **ArrayBuffer**. This API u
**Example**
```js
pixelmap.readPixelsToBuffer(readBuffer).then(() => {
// Called if the condition is met.
}).catch(error => {
// Called if no condition is met.
})
pixelmap.readPixelsToBuffer(ReadBuffer).then(() => {
console.log('readPixelsToBuffer succeeded.'); // Called if the condition is met.
}).catch(error => {
console.log('readPixelsToBuffer failed.'); // Called if no condition is met.
})
```
### readPixelsToBuffer<sup>7+</sup>
......@@ -120,8 +125,13 @@ Reads image pixel map data and writes the data to an **ArrayBuffer**. This API u
**Example**
```js
pixelmap.readPixelsToBuffer(readBuffer, () => {
})
pixelmap.readPixelsToBuffer(ReadBuffer, (err, res) => {
if(err) {
console.log('readPixelsToBuffer failed.'); // Called if no condition is met.
} else {
console.log('readPixelsToBuffer succeeded.'); // Called if the condition is met.
}
})
```
### readPixels<sup>7+</sup>
......@@ -147,11 +157,11 @@ Reads image pixel map data in an area. This API uses a promise to return the dat
**Example**
```js
pixelmap.readPixels(area).then((data) => {
// Called if the condition is met.
}).catch(error => {
// Called if no condition is met.
})
pixelmap.readPixels(Area).then((data) => {
console.log('readPixels succeeded.'); // Called if the condition is met.
}).catch(error => {
console.log('readPixels failed.'); // Called if no condition is met.
})
```
### readPixels<sup>7+</sup>
......@@ -174,19 +184,17 @@ Reads image pixel map data in an area. This API uses an asynchronous callback to
```js
let opts = { editable: true, pixelFormat: 3, size: { height: 4, width: 6 } }
image.createPixelMap(color, opts, (err, pixelmap) => {
if(pixelmap == undefined){
console.info('createPixelMap failed');
expect(false).assertTrue();
done();
}else{
const area = { pixels: new ArrayBuffer(8),
offset: 0,
stride: 8,
region: { size: { height: 1, width: 2 }, x: 0, y: 0 }}
pixelmap.readPixels(area, () => {
console.info('readPixels success');
})
}
if(pixelmap == undefined){
console.info('createPixelMap failed.');
} else {
const area = { pixels: new ArrayBuffer(8),
offset: 0,
stride: 8,
region: { size: { height: 1, width: 2 }, x: 0, y: 0 }};
pixelmap.readPixels(area, () => {
console.info('readPixels success');
})
}
})
```
......@@ -218,16 +226,14 @@ let opts = { editable: true, pixelFormat: 3, size: { height: 4, width: 6 } }
image.createPixelMap(color, opts)
.then( pixelmap => {
if (pixelmap == undefined) {
console.info('createPixelMap failed');
expect(false).assertTrue()
done();
console.info('createPixelMap failed.');
}
const area = { pixels: new ArrayBuffer(8),
offset: 0,
stride: 8,
region: { size: { height: 1, width: 2 }, x: 0, y: 0 }
}
var bufferArr = new Uint8Array(area.pixels);
let bufferArr = new Uint8Array(area.pixels);
for (var i = 0; i < bufferArr.length; i++) {
bufferArr[i] = i + 1;
}
......@@ -240,11 +246,8 @@ image.createPixelMap(color, opts)
region: { size: { height: 1, width: 2 }, x: 0, y: 0 }
}
})
})
.catch(error => {
}).catch(error => {
console.log('error: ' + error);
expect().assertFail();
done();
})
```
......@@ -261,19 +264,23 @@ Writes image pixel map data to an area. This API uses an asynchronous callback t
| Name | Type | Mandatory| Description |
| --------- | ------------------------------ | ---- | ------------------------------ |
| area | [PositionArea](#positionarea7) | Yes | Area to which the image pixel map data will be written. |
| callback: | AsyncCallback\<void> | Yes | Callback used to return the operation result. If the operation fails, an error message is returned.|
| callback: | AsyncCallback\<void> | Yes | Callback used to return the operation result. If the operation fails, `error` contains an error object.|
**Example**
```js
pixelmap.writePixels(area, () => {
const readArea = {
pixels: new ArrayBuffer(20),
offset: 0,
stride: 8,
region: { size: { height: 1, width: 2 }, x: 0, y: 0 },
}
})
pixelmap.writePixels(Area, (error) => {
if (error!=undefined) {
console.info('writePixels failed.');
} else {
const readArea = {
pixels: new ArrayBuffer(20),
offset: 0,
stride: 8,
region: { size: { height: 1, width: 2 }, x: 0, y: 0 },
}
}
})
```
### writeBufferToPixels<sup>7+</sup>
......@@ -299,11 +306,11 @@ Reads image data in an **ArrayBuffer** and writes the data to a **PixelMap** obj
**Example**
```js
pixelMap.writeBufferToPixels(colorBuffer).then(() => {
PixelMap.writeBufferToPixels(color).then(() => {
console.log("Succeeded in writing data from a buffer to a PixelMap.");
}).catch((err) => {
console.error("Failed to write data from a buffer to a PixelMap.");
});
})
```
### writeBufferToPixels<sup>7+</sup>
......@@ -324,12 +331,13 @@ Reads image data in an **ArrayBuffer** and writes the data to a **PixelMap** obj
**Example**
```js
pixelMap.writeBufferToPixels(colorBuffer, function(err) {
PixelMap.writeBufferToPixels(color, function(err) {
if (err) {
console.error("Failed to write data from a buffer to a PixelMap.");
return;
}
console.log("Succeeded in writing data from a buffer to a PixelMap.");
} else {
console.log("Succeeded in writing data from a buffer to a PixelMap.");
}
});
```
......@@ -350,7 +358,7 @@ Obtains pixel map information of this image. This API uses a promise to return t
**Example**
```js
pixelMap.getImageInfo().then(function(info) {
PixelMap.getImageInfo().then(function(info) {
console.log("Succeeded in obtaining the image pixel map information.");
}).catch((err) => {
console.error("Failed to obtain the image pixel map information.");
......@@ -374,7 +382,11 @@ Obtains pixel map information of this image. This API uses an asynchronous callb
**Example**
```js
pixelmap.getImageInfo((imageInfo) => {})
pixelmap.getImageInfo((imageInfo) => {
console.log("getImageInfo succeeded.");
}).catch((err) => {
console.error("getImageInfo failed.");
})
```
### getBytesNumberPerRow<sup>7+</sup>
......@@ -394,7 +406,9 @@ Obtains the number of bytes per line of the image pixel map.
**Example**
```js
rowCount = pixelmap.getBytesNumberPerRow()
image.createPixelMap(clolr, opts, (err,pixelmap) => {
let rowCount = pixelmap.getBytesNumberPerRow();
})
```
### getPixelBytesNumber<sup>7+</sup>
......@@ -414,7 +428,7 @@ Obtains the total number of bytes of the image pixel map.
**Example**
```js
pixelBytesNumber = pixelmap.getPixelBytesNumber()
let pixelBytesNumber = pixelmap.getPixelBytesNumber();
```
### release<sup>7+</sup>
......@@ -434,8 +448,13 @@ Releases this **PixelMap** object. This API uses a promise to return the result.
**Example**
```js
pixelmap.release().then(() => { })
.catch(error => {})
image.createPixelMap(color, opts, (pixelmap) => {
pixelmap.release().then(() => {
console.log('release succeeded.');
}).catch(error => {
console.log('release failed.');
})
})
```
### release<sup>7+</sup>
......@@ -455,7 +474,13 @@ Releases this **PixelMap** object. This API uses an asynchronous callback to ret
**Example**
```js
pixelmap.release(()=>{ })
image.createPixelMap(color, opts, (pixelmap) => {
pixelmap.release().then(() => {
console.log('release succeeded.');
}).catch(error => {
console.log('release failed.');
})
})
```
## image.createImageSource
......@@ -508,7 +533,7 @@ Creates an **ImageSource** instance based on the file descriptor.
**Example**
```js
const imageSourceApi = image.createImageSource(0)
const imageSourceApi = image.createImageSource(0);
```
## ImageSource
......@@ -517,9 +542,11 @@ Provides APIs to obtain image information. Before calling any API in **ImageSour
### Attributes
**System capability**: SystemCapability.Multimedia.Image
| Name | Type | Readable| Writable| Description |
| ---------------- | -------------- | ---- | ---- | ------------------------------------------------------------ |
| supportedFormats | Array\<string> | Yes | No | Supported image formats, including png, jpeg, wbmp, bmp, gif, webp, and heif.<br>**System capability**: SystemCapability.Multimedia.Image|
| supportedFormats | Array\<string> | Yes | No | Supported image formats, including png, jpeg, wbmp, bmp, gif, webp, and heif.|
### getImageInfo
......@@ -539,7 +566,13 @@ Obtains information about an image with the specified index. This API uses an as
**Example**
```js
imageSourceApi.getImageInfo(0,(error, imageInfo) => {})
imageSourceApi.getImageInfo(0,(error, imageInfo) => {
if(error) {
console.log('getImageInfo failed.');
} else {
console.log('getImageInfo succeeded.');
}
})
```
### getImageInfo
......@@ -559,7 +592,11 @@ Obtains information about this image. This API uses an asynchronous callback to
**Example**
```js
imageSourceApi.getImageInfo(imageInfo => {})
imageSourceApi.getImageInfo(imageInfo => {
console.log('getImageInfo succeeded.');
}).catch(error => {
console.log('getImageInfo failed.');
})
```
### getImageInfo
......@@ -586,8 +623,11 @@ Obtains information about an image with the specified index. This API uses a pro
```js
imageSourceApi.getImageInfo(0)
.then(imageInfo => {})
.catch(error => {})
.then(imageInfo => {
console.log('getImageInfo succeeded.');
}).catch(error => {
console.log('getImageInfo failed.');
})
```
### getImageProperty<sup>7+</sup>
......@@ -615,8 +655,11 @@ Obtains the value of a property with the specified index in this image. This API
```js
imageSourceApi.getImageProperty("BitsPerSample")
.then(data => {})
.catch(error => {})
.then(data => {
console.log('getImageProperty succeeded.');
}).catch(error => {
console.log('getImageProperty failed.');
})
```
### getImageProperty<sup>7+</sup>
......@@ -637,7 +680,13 @@ Obtains the value of a property with the specified index in this image. This API
**Example**
```js
imageSourceApi.getImageProperty("BitsPerSample",(error,data) => {})
imageSourceApi.getImageProperty("BitsPerSample",(error,data) => {
if(error) {
console.log('getImageProperty failed.');
} else {
console.log('getImageProperty succeeded.');
}
})
```
### getImageProperty<sup>7+</sup>
......@@ -659,7 +708,13 @@ Obtains the value of a property in this image. This API uses an asynchronous cal
**Example**
```js
imageSourceApi.getImageProperty("BitsPerSample",property,(error,data) => {})
imageSourceApi.getImageProperty("BitsPerSample",Property,(error,data) => {
if(error) {
console.log('getImageProperty failed.');
} else {
console.log('getImageProperty succeeded.');
}
})
```
### createPixelMap<sup>7+</sup>
......@@ -685,8 +740,11 @@ Creates a **PixelMap** object based on image decoding parameters. This API uses
**Example**
```js
imageSourceApi.createPixelMap().then(pixelmap => {})
.catch(error => {})
imageSourceApi.createPixelMap().then(pixelmap => {
console.log('createPixelMap succeeded.');
}).catch(error => {
console.log('createPixelMap failed.');
})
```
### createPixelMap<sup>7+</sup>
......@@ -706,7 +764,11 @@ Creates a **PixelMap** object based on the default parameters. This API uses an
**Example**
```js
imageSourceApi.createPixelMap(pixelmap => {})
imageSourceApi.createPixelMap(pixelmap => {
console.log('createPixelMap succeeded.');
}).catch(error => {
console.log('createPixelMap failed.');
})
```
### createPixelMap<sup>7+</sup>
......@@ -727,7 +789,11 @@ Creates a **PixelMap** object based on image decoding parameters. This API uses
**Example**
```js
imageSourceApi.createPixelMap(decodingOptions, pixelmap => {})
imageSourceApi.createPixelMap(decodingOptions, pixelmap => {
console.log('createPixelMap succeeded.');
}).catch(error => {
console.log('createPixelMap failed.');
})
```
### release
......@@ -747,7 +813,11 @@ Releases this **ImageSource** instance. This API uses an asynchronous callback t
**Example**
```js
imageSourceApi.release(() => {})
imageSourceApi.release(() => {
console.log('release succeeded.');
}).catch(error => {
console.log('release failed.');
})
```
### release
......@@ -767,7 +837,11 @@ Releases this **ImageSource** instance. This API uses a promise to return the re
**Example**
```js
imageSourceApi.release().then(()=>{ }).catch(error => {})
imageSourceApi.release().then(()=>{
console.log('release succeeded.');
}).catch(error => {
console.log('release failed.');
})
```
## image.createImagePacker
......@@ -796,9 +870,11 @@ Provide APIs to pack images. Before calling any API in **ImagePacker**, you must
### Attributes
| Name | Type | Readable| Writable| Description |
| ---------------- | -------------- | ---- | ---- | ------------------------------------------------------------ |
| supportedFormats | Array\<string> | Yes | No | Supported image format, which can be jpeg.<br>**System capability**: SystemCapability.Multimedia.Image|
**System capability**: SystemCapability.Multimedia.Image
| Name | Type | Readable| Writable| Description |
| ---------------- | -------------- | ---- | ---- | -------------------------- |
| supportedFormats | Array\<string> | Yes | No | Supported image format, which can be jpeg.|
### packing
......@@ -814,13 +890,13 @@ Packs an image. This API uses an asynchronous callback to return the result.
| -------- | ---------------------------------- | ---- | ---------------------------------- |
| source | [ImageSource](#imagesource) | Yes | Image to pack. |
| option | [PackingOption](#packingoption) | Yes | Option for image packing. |
| callback | AsyncCallback\<ArrayBuffer> | Yes | Callback used to return the packed data.|
| callback | AsyncCallback\<ArrayBuffer> | Yes | Callback used to return the packed data.|
**Example**
```js
let packOpts = { format:["image/jpeg"], quality:98 }
imagePackerApi.packing(imageSourceApi, packOpts, data => {})
let packOpts = { format:"image/jpeg", quality:98 };
imagePackerApi.packing(ImageSourceApi, packOpts, data => {})
```
### packing
......@@ -848,9 +924,12 @@ Packs an image. This API uses a promise to return the result.
```js
let packOpts = { format:["image/jpeg"], quality:98 }
imagePackerApi.packing(imageSourceApi, packOpts)
.then( data => { })
.catch(error => {})
imagePackerApi.packing(ImageSourceApi, packOpts)
.then( data => {
console.log('packing succeeded.');
}).catch(error => {
console.log('packing failed.');
})
```
### packing<sup>8+</sup>
......@@ -873,7 +952,11 @@ Packs an image. This API uses an asynchronous callback to return the result.
```js
let packOpts = { format:["image/jpeg"], quality:98 }
imagePackerApi.packing(pixelMapApi, packOpts, data => {})
imagePackerApi.packing(PixelMapApi, packOpts, data => {
console.log('packing succeeded.');
}).catch(error => {
console.log('packing failed.');
})
```
### packing<sup>8+</sup>
......@@ -886,10 +969,10 @@ Packs an image. This API uses a promise to return the result.
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------------------------------- | ---- | -------------- |
| Name| Type | Mandatory| Description |
| ------ | ------------------------------- | ---- | ------------------ |
| source | [PixelMap](#pixelmap) | Yes | **PixelMap** object to pack.|
| option | [PackingOption](#packingoption) | Yes | Option for image packing.|
| option | [PackingOption](#packingoption) | Yes | Option for image packing. |
**Return value**
......@@ -901,9 +984,12 @@ Packs an image. This API uses a promise to return the result.
```js
let packOpts = { format:["image/jpeg"], quality:98 }
imagePackerApi.packing(pixelMapApi, packOpts)
.then( data => { })
.catch(error => {})
imagePackerApi.packing(PixelMapApi, packOpts)
.then( data => {
console.log('packing succeeded.');
}).catch(error => {
console.log('packing failed.');
})
```
### release
......@@ -923,7 +1009,11 @@ Releases this **ImagePacker** instance. This API uses an asynchronous callback t
**Example**
```js
imagePackerApi.release(()=>{})
imagePackerApi.release(()=>{
console.log('release succeeded.');
}).catch(error => {
console.log('release failed.');
})
```
### release
......@@ -943,8 +1033,390 @@ Releases this **ImagePacker** instance. This API uses a promise to return the re
**Example**
```js
imagePackerApi.release().then(()=>{
}).catch((error)=>{})
imagePackerApi.release().then(()=>{
console.log('release succeeded.');
}).catch((error)=>{
console.log('release failed.');
})
```
## image.createImageReceiver<sup>9+</sup>
createImageReceiver(width: number, height: number, format: number, capacity: number): ImageReceiver
Create an **ImageReceiver** instance by specifying the image width, height, format, and capacity.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------ | ---- | ---------------------- |
| width | number | Yes | Default image width. |
| height | number | Yes | Default image height. |
| format | number | Yes | Image format. |
| capacity | number | Yes | Maximum number of images that can be accessed at the same time.|
**Return value**
| Type | Description |
| -------------------------------- | --------------------------------------- |
| [ImageReceiver](#imagereceiver9) | Returns an **ImageReceiver** instance if the operation is successful.|
**Example**
```js
var receiver = image.createImageReceiver(8192, 8, 4, 8);
```
## ImageReceiver<sup>9+</sup>
Provides APIs to obtain the surface ID of a component, read the latest image, read the next image, and release the **ImageReceiver** instance.
Before calling any APIs in **ImageReceiver**, you must create an **ImageReceiver** instance.
### Attributes
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
| Name | Type | Readable| Writable| Description |
| --------------------- | ---------------------------- | ---- | ---- | ------------------ |
| size<sup>9+</sup> | [Size](#size) | Yes | No | Image size. |
| capacity<sup>9+</sup> | number | Yes | No | Maximum number of images that can be accessed at the same time.|
| format<sup>9+</sup> | [ImageFormat](#imageformat9) | Yes | No | Image format. |
### getReceivingSurfaceId<sup>9+</sup>
getReceivingSurfaceId(callback: AsyncCallback\<string>): void
Obtains a surface ID for the camera or other components. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ---------------------- | ---- | -------------------------- |
| callback | AsyncCallback\<string> | Yes | Callback used to return the surface ID.|
**Example**
```js
receiver.getReceivingSurfaceId((err, id) => {
if(err) {
console.log('getReceivingSurfaceId failed.');
} else {
console.log('getReceivingSurfaceId succeeded.');
}
});
```
### getReceivingSurfaceId<sup>9+</sup>
getReceivingSurfaceId(): Promise\<string>
Obtains a surface ID for the camera or other components. This API uses a promise to return the result.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Return value**
| Type | Description |
| ---------------- | -------------------- |
| Promise\<string> | Promise used to return the surface ID.|
**Example**
```js
receiver.getReceivingSurfaceId().then( id => {
console.log('getReceivingSurfaceId succeeded.');
}).catch(error => {
console.log('getReceivingSurfaceId failed.');
})
```
### readLatestImage<sup>9+</sup>
readLatestImage(callback: AsyncCallback\<Image>): void
Reads the latest image from the **ImageReceiver** instance. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------- | ---- | ------------------------ |
| callback | AsyncCallback<[Image](#image9)> | Yes | Callback used to return the latest image.|
**Example**
```js
receiver.readLatestImage((err, img) => {
if(err) {
console.log('readLatestImage failed.');
} else {
console.log('readLatestImage succeeded.');
}
});
```
### readLatestImage<sup>9+</sup>
readLatestImage(): Promise\<Image>
Reads the latest image from the **ImageReceiver** instance. This API uses a promise to return the result.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Return value**
| Type | Description |
| ------------------------- | ------------------ |
| Promise<[Image](#image8)> | Promise used to return the latest image.|
**Example**
```js
receiver.readLatestImage().then(img => {
console.log('readLatestImage succeeded.');
}).catch(error => {
console.log('readLatestImage failed.');
})
```
### readNextImage<sup>9+</sup>
readNextImage(callback: AsyncCallback\<Image>): void
Reads the next image from the **ImageReceiver** instance. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------- | ---- | -------------------------- |
| callback | AsyncCallback<[Image](#image9)> | Yes | Callback used to return the next image.|
**Example**
```js
receiver.readNextImage((err, img) => {
if(err) {
console.log('readNextImage failed.');
} else {
console.log('readNextImage succeeded.');
}
});
```
### readNextImage<sup>9+</sup>
readNextImage(): Promise\<Image>
Reads the next image from the **ImageReceiver** instance. This API uses a promise to return the result.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Return value**
| Type | Description |
| ------------------------- | -------------------- |
| Promise<[Image](#image9)> | Promise used to return the next image.|
**Example**
```js
receiver.readNextImage().then(img => {
console.log('readNextImage succeeded.');
}).catch(error => {
console.log('readNextImage failed.');
})
```
### on('imageArrival')<sup>9+</sup>
on(type: 'imageArrival', callback: AsyncCallback\<void>): void
Listens for image arrival events.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | -------------------- | ---- | ------------------------------------------------------ |
| type | string | Yes | Type of event to listen for. The value is fixed at **imageArrival**, which is triggered when an image is received.|
| callback | AsyncCallback\<void> | Yes | Callback invoked for the event. |
**Example**
```js
receiver.on('imageArrival', () => {})
```
### release<sup>9+</sup>
release(callback: AsyncCallback\<void>): void
Releases this **ImageReceiver** instance. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | -------------------- | ---- | ------------------------ |
| callback | AsyncCallback\<void> | Yes | Callback used to return the result.|
**Example**
```js
receiver.release(() => {})
```
### release<sup>9+</sup>
release(): Promise\<void>
Releases this **ImageReceiver** instance. This API uses a promise to return the result.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
**Return value**
| Type | Description |
| -------------- | ------------------ |
| Promise\<void> | Promise used to return the result.|
**Example**
```js
receiver.release().then(() => {
console.log('release succeeded.');
}).catch(error => {
console.log('release failed.');
})
```
## Image<sup>9+</sup>
Provides APIs for basic image operations, including obtaining image information and reading and writing image data. An **Image** instance is returned when [readNextImage](#readnextimage9) and [readLatestImage](#readlatestimage9) are called.
### Attributes
**System capability**: SystemCapability.Multimedia.Image.Core
| Name | Type | Readable| Writable| Description |
| --------------------- | ------------------ | ---- | ---- | -------------------------------------------------- |
| clipRect<sup>9+</sup> | [Region](#region7) | Yes | Yes | Image area to be cropped. |
| size<sup>9+</sup> | [Size](#size) | Yes | No | Image size. |
| format<sup>9+</sup> | number | Yes | No | Image format. For details, see [PixelMapFormat](#pixelmapformat7).|
### getComponent<sup>9+</sup>
getComponent(componentType: ComponentType, callback: AsyncCallback\<Component>): void
Obtains the component buffer from the **Image** instance based on the color component type. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.Multimedia.Image.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------------- | --------------------------------------- | ---- | -------------------- |
| componentType | [ComponentType](#componenttype9) | Yes | Color component type of the image. |
| callback | AsyncCallback<[Component](#component9)> | Yes | Callback used to return the component buffer.|
**Example**
```js
img.getComponent(4, (err, component) => {
if(err) {
console.log('getComponent failed.');
} else {
console.log('getComponent succeeded.');
}
})
```
### getComponent<sup>9+</sup>
getComponent(componentType: ComponentType): Promise\<Component>
Obtains the component buffer from the **Image** instance based on the color component type. This API uses a promise to return the result.
**System capability**: SystemCapability.Multimedia.Image.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------------- | -------------------------------- | ---- | ---------------- |
| componentType | [ComponentType](#componenttype9) | Yes | Color component type of the image.|
**Return value**
| Type | Description |
| --------------------------------- | --------------------------------- |
| Promise<[Component](#component9)> | Promise used to return the component buffer.|
**Example**
```js
img.getComponent(4).then(component => { })
```
### release<sup>9+</sup>
release(callback: AsyncCallback\<void>): void
Releases this **Image** instance. This API uses an asynchronous callback to return the result.
The corresponding resources must be released before another image arrives.
**System capability**: SystemCapability.Multimedia.Image.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | -------------------- | ---- | -------------- |
| callback | AsyncCallback\<void> | Yes | Callback used to return the result.|
**Example**
```js
img.release(() =>{
console.log('release succeeded.');
}).catch(error => {
console.log('release failed.');
})
```
### release<sup>9+</sup>
release(): Promise\<void>
Releases this **Image** instance. This API uses a promise to return the result.
The corresponding resources must be released before another image arrives.
**System capability**: SystemCapability.Multimedia.Image.Core
**Return value**
| Type | Description |
| -------------- | --------------------- |
| Promise\<void> | Promise used to return the result.|
**Example**
```js
img.release().then(() =>{
console.log('release succeeded.');
}).catch(error => {
console.log('release failed.');
})
```
## PositionArea<sup>7+</sup>
......@@ -957,7 +1429,7 @@ Describes area information in an image.
| ------ | ------------------ | ---- | ---- | ------------------------------------------------------------ |
| pixels | ArrayBuffer | Yes | No | Pixels of the image. |
| offset | number | Yes | No | Offset for data reading. |
| stride | number | Yes | No | Number of bytes from one row of pixels in memory to the next row of pixels in memory. The value of **stride** must be greater than or equal to the value of **region.size.width** multiplied by 4. |
| stride | number | Yes | No | Number of bytes from one row of pixels in memory to the next row of pixels in memory. The value of **stride** must be greater than or equal to the value of **region.size.width** multiplied by 4. |
| region | [Region](#region7) | Yes | No | Region to read or write. The width of the region to write plus the X coordinate cannot be greater than the width of the original image. The height of the region to write plus the Y coordinate cannot be greater than the height of the original image.|
## ImageInfo
......@@ -983,7 +1455,7 @@ Describes the size of an image.
## PixelMapFormat<sup>7+</sup>
Enumerates pixel map formats.
Enumerates the pixel formats of images.
**System capability**: SystemCapability.Multimedia.Image
......@@ -995,7 +1467,7 @@ Enumerates pixel map formats.
## AlphaType<sup>9+</sup>
Enumerates alpha types.
Enumerates the alpha types of images.
**System capability**: SystemCapability.Multimedia.Image
......@@ -1008,7 +1480,7 @@ Enumerates alpha types.
## ScaleMode<sup>9+</sup>
Enumerates scale modes.
Enumerates the scale modes of images.
**System capability**: SystemCapability.Multimedia.Image
......@@ -1019,19 +1491,21 @@ Enumerates scale modes.
## InitializationOptions<sup>8+</sup>
Defines pixel map initialization options.
**System capability**: SystemCapability.Multimedia.Image
| Name | Type | Readable| Writable| Description |
| ----------- | ---------------------------------- | ---- | ---- | -------------- |
| alphaType<sup>9+</sup> | [AlphaType](#alphatype9) | Yes | Yes | Alpha type. |
| editable | boolean | Yes | Yes | Whether the image is editable. |
| pixelFormat | [PixelMapFormat](#pixelmapformat7) | Yes | Yes | Pixel map format. |
| scaleMode<sup>9+</sup> | [ScaleMode](#scalemode9) | Yes | Yes | Scale mode. |
| size | [Size](#size) | Yes | Yes | Image size.|
| Name | Type | Readable| Writable| Description |
| ---------------------- | ---------------------------------- | ---- | ---- | -------------- |
| alphaType<sup>9+</sup> | [AlphaType](#alphatype9) | Yes | Yes | Alpha type. |
| editable | boolean | Yes | Yes | Whether the image is editable. |
| pixelFormat | [PixelMapFormat](#pixelmapformat7) | Yes | Yes | Pixel map format. |
| scaleMode<sup>9+</sup> | [ScaleMode](#scalemode9) | Yes | Yes | Scale mode. |
| size | [Size](#size) | Yes | Yes | Image size.|
## DecodingOptions<sup>7+</sup>
Describes the decoding options.
Defines image decoding options.
**System capability**: SystemCapability.Multimedia.Image
......@@ -1043,7 +1517,7 @@ Describes the decoding options.
| desiredSize | [Size](#size) | Yes | Yes | Expected output size. |
| desiredRegion | [Region](#region7) | Yes | Yes | Region to decode. |
| desiredPixelFormat | [PixelMapFormat](#pixelmapformat7) | Yes | Yes | Pixel map format for decoding.|
| index | numer | Yes | Yes | Index of the image to decode. |
| index | number | Yes | Yes | Index of the image to decode. |
## Region<sup>7+</sup>
......@@ -1066,7 +1540,7 @@ Describes the option for image packing.
| Name | Type | Readable| Writable| Description |
| ------- | ------ | ---- | ---- | -------------- |
| format | string | Yes | Yes | Format of the packed image. |
| quality | number | Yes | Yes | Quality of the packed image.|
| quality | number | Yes | Yes | Quality of the output image during JPEG encoding. The value ranges from 1 to 100.|
## GetImagePropertyOptions<sup>7+</sup>
......@@ -1095,3 +1569,40 @@ Describes the exchangeable image file format (Exif) information of an image.
| GPS_LONGITUDE | "GPSLongitude" | Image longitude. |
| GPS_LATITUDE_REF | "GPSLatitudeRef" | Latitude reference, for example, N or S.|
| GPS_LONGITUDE_REF | "GPSLongitudeRef" | Longitude reference, for example, W or E.|
## ImageFormat<sup>9+</sup>
Enumerates the image formats.
**System capability**: SystemCapability.Multimedia.Image.Core
| Name | Default Value| Description |
| ------------ | ------ | -------------------- |
| YCBCR_422_SP | 1000 | YCBCR422 semi-planar format.|
| JPEG | 2000 | JPEG encoding format. |
## ComponentType<sup>9+</sup>
Enumerates the color component types of images.
**System capability**: SystemCapability.Multimedia.Image.ImageReceiver
| Name | Default Value| Description |
| ----- | ------ | ----------- |
| YUV_Y | 1 | Luminance component. |
| YUV_U | 2 | Chrominance component. |
| YUV_V | 3 | Chrominance component. |
| JPEG | 4 | JPEG type.|
## Component<sup>9+</sup>
Describes the color components of an image.
**System capability**: SystemCapability.Multimedia.Image.Core
| Name | Type | Readable| Writable| Description |
| ------------- | -------------------------------- | ---- | ---- | ------------ |
| componentType | [ComponentType](#componenttype9) | Yes | No | Color component type. |
| rowStride | number | Yes | No | Row stride. |
| pixelStride | number | Yes | No | Pixel stride. |
| byteBuffer | ArrayBuffer | Yes | No | Component buffer.|
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