DFimageio

DFimageio — Request a study CRF image from the database

Synopsis

DFimageio [-hd] [-f string] {-s #} {imageID}

Description

DFimageio fetches a specific, single CRF image from the requested study database and writes it in its native format to a file, or standard output.

The study number and the unique CRF image identifier are required arguments. The CRF image identifier must be one of:

  • a database image identifier, written in the YYWW/SSSSPPP notation,

  • a DFsetup background identifier, written using the notation $plt###.png [9] where ### is the plate number, or

  • an DFexplore background identifier, written using the notation $DFbkgd###.png [9] where ### is the plate number

Study CRF images are stored in the study file system and hence can also be accessed using standard shell commands. However, shell commands will fail to access the CRF image if:

  • the CRF image resides on a file system which is not visible to the current computer

  • filesystem permissions prevent the file from being read

  • the CRF image was previously deleted when the database record which it references was deleted

DFimageio is the correct, accepted method for accessing CRF image contents from the study database. Future releases of DFdiscover will further tighten the permissions on the CRF image files so that DFimageio will be the only method for retrieving them reliably.

Options

-hd

Request the HD version of the database image. If available, the HD version is returned; if not available, or if HD is not requested, the standard definition image is returned. This is applicable to database images only - the DFsetup and DFexplore backgrounds are available in only one definition. [10]

-f string

write the retrieved CRF image to the named file. Without this option, the retrieved CRF image is written to standard output where it should be re-directed using shell syntax.

-s #

the study number (required).

imageID

the unique identifier for the CRF image (required).

Exit Status

DFimageio exits with one of the following statuses:

0

The command was successful.

36

The required command-line arguments were not present or were incorrectly specified.

1

The requested CRF image could not be located using the supplied image identifier.

Examples

Example 3.53. Get and write a requested CRF image to a file

% DFimageio -f image1 -s 254 1525/0008001

The CRF image with the unique identifier 1525/0008001 is written to the file named image1 in the current directory.


Example 3.54. Get and re-direct a requested CRF image to a file

% DFimageio -s 254 1525/0008001 > image1

The CRF image with the unique identifier 1525/0008001 is written to the file named image1 in the current directory. The result is identical to that in the previous example but uses shell re-direction to achieve it.


Example 3.55. Get and write a DFsetup background image to a file

% DFimageio -f image1 -s 254 \$plt001.png

The DFsetup background image with the unique identifier plt001 is written to the file named image1 in the current directory.




[9] The $ character may need to be escaped with a backslash to avoid interpretation as a shell variable.

[10] Combining -hd with $plt###.png or $DFbkgd###.png will silently ignore the -hd argument.