Leer imagen de la carpeta Pictures de Android

[Casimiro Notevi]

Si no he entendido mal, insisto que con ContentChooser puedes acceder a otros carpetas:

ContentChooser
The ContentChooser object allows the user to select a specific type of content using other installed applications.
For example the user can use the internal Gallery application to select an image.
If the user has installed a file manager then the ContentChooser can be used to select general files.
This object should usually be declared as a process global object.
After initializing the object you can let the user select content by calling Show with the required MIME types.
The Result event will be raised with a Success flag and with the content Dir and FileName.
Note that these values may point to resources other than regular files. Still you can pass them to methods that expect Dir and FileName.
Only content types that can be opened with an InputStream are supported.