How can I paste image from clipboard and save into image_field ?
You could try the FileField Sources module. It provides quite a few additional options to upload files.
- Re-use files by an auto-complete textfield
- Attach server-side files uploaded via FTP
- Transfer files from a remote server (cURL required)
- Paste a file directly from the clipboard (Drupal 7 only)
- Select existing files through the IMCE file browser