Update docs against 16661+16824

Signed-off-by: wusongqing<wusongqing@huawei.com>

en/application-dev/reference/apis/js-apis-image.md

@@ -80,9 +80,9 @@ image.createPixelMap(color, opts, (error, pixelmap) => {
 
 ## PixelMap<sup>7+</sup>
 
-Provides APIs to read or write image pixel map data and obtain image pixel map information. Before calling any API in **PixelMap**, you must use **createPixelMap** to create a **PixelMap** object.
+Provides APIs to read or write image pixel map data and obtain image pixel map information. Before calling any API in **PixelMap**, you must use **createPixelMap** to create a **PixelMap** object. Currently, the maximum size of a serialized pixel map is 128 MB. A larger size will cause a display failure. The size is calculated as follows: Width * Height * Number of bytes occupied by each pixel.
 
- ### Attributes
+### Attributes
 
 **System capability**: SystemCapability.Multimedia.Image.Core
 
@@ -949,7 +949,7 @@ Creates an **ImageSource** instance based on the URI.
 
 ```js
 let context = featureAbility.getContext();
-let path = context.getCacheDir() + "test.jpg";
+let path = context.cacheDir() + "test.jpg";
 const imageSourceApi = image.createImageSource(path);
 ```
 
@@ -2548,7 +2548,7 @@ Describes image properties.
 
 ## PropertyKey<sup>7+</sup>
 
-Describes the exchangeable image file format (EXIF) information of an image.
+Describes the exchangeable image file format (EXIF) data of an image.
 
 **System capability**: SystemCapability.Multimedia.Image.Core