Using image fields
Designer has two types of image
Image objects let you add a read-only image that users
cannot edit on the form. This object is useful for enhancing the
look of the form. For more information about this type of image
object, see Using images.
Image field objects let you add an image that can be changed
in an interactive form.
Image fields can be bound to an external data source or they
can be scripted. Image fields support the merging of external image
data through binding. When the data source contains a value for
an image field, the image is rendered in the form. With this capability,
images can be selected and loaded dynamically. For example, a form
can enable users to choose catalog items and, through scripting, a
picture of each item could be displayed as a result. If the form
contains an empty image field, the path to the image identifies
which image to display in the form.
images in image field objects can be updated when the form is opened
in Acrobat and Adobe Reader 7.0.5 and later. Interactive images
become read-only and cannot be updated when the form is opened in Acrobat
6.0.2 and Adobe Reader 6.0.2. However, through scripting in an interactive PDF
or HTML form created by Forms, a user could request the same form
again merged with a different image.
Image field objects support these file formats:
- Windows Bitmap (BMP)
- Designer supports BMP images.
- Joint Photographic Experts Group variations (JPG)
- Designer supports JPG images that include digital camera
Exchangeable Image File (EXIF) data.
- Graphics Interchange Format (GIF)
- Although Designer supports GIF images, animated GIF files
are not supported. Designer also supports transparency within GIF
files to allow for overlaying images on forms.
- Portable Network Graphics (PNG)
- Designer supports one transparency color within PNG files
to allow for overlaying images on forms.
- Tagged Image File (TIF)
- Designer supports Monochrome (1 color component 1-bit depth),
Greyscale (1 color component 8-bit depth), RGB (3 color components
8-bit depth), and Palette (1 color component 1,2,4,8-bit depths)
An initial (default) image to insert at run time
can be specified by either a file name or a Uniform Resource Locator
(URL). Initially, the image is linked, which means that it is stored
separately from the form and displayed when the form is opened.
Alternatively, the image data can be embedded in the form when the form
Important: Linking to an image is
not a secure way to protect sensitive business data. If the image
data is considered sensitive, you should embed it in the form. Also, you
can use a secure HTTPS connection in conjunction with a URL. However,
HTTPS protects the transmission of the image data only while the
data is being transmitted; it does not protect access to the image
(that is, no authentication is performed).
After you add
an image field to the form design, you can manipulate the object’s properties
in the Object palette. You can choose to define these properties:
Keep in mind that if the image file or a link to the image file
is in the data file, the image only appears when the form is rendered
and is not visible when you are designing the form. Also, if you
plan on using the form offline, select the Embed Image Data option
in the Field tab in the Object palette so that all components of
the form are available.
To specify an initial (default) image to link
In the Object palette, click the
Do one of the following actions:
If you know
the location of the image file, in the URL box, type the URL to the
image file and press Enter.
To browse for the location of the image file, click the Browse
button to the
right of the URL box, navigate to the image file that you want to
insert and click Open.
Note: To use
relative path names for retrieving linked images when the form is
opened, the image files must be stored in a folder that is accessible
to users. If Forms is available, the path must be relative to Forms.
To embed image data in the form when the form is created
In the Object palette, click the
Field tab and select Embed Image Data.
When you embed the
image in the form, a copy of the image information is stored in
the form. If the image field will be used to load images dynamically when
the form is rendered, do not select the Embed Image Data option.
To know more about the differences between embedding versus linking
images, see this article.
you are using the paper forms barcode object, you should not select
the Embed Image Data option unless you have assigned a collection,
that does not include image fields, to the barcode. The embedded
image data is larger than the paper forms barcode object can hold.
To size an image
In the Object palette, click the Field tab.
In the Sizing list, select one of these options to determine
what happens when the image is loaded:
To resize the
image in the object, ensure that the aspect ratio of the image is
preserved, and select Scale Image Proportionally.
To resize the image to match the dimensions of the object,
select Scale Image to Fit Rectangle. The aspect ratio of the image
is not preserved.
To preserve the actual size of the image, select Use Original
Size. The image is not resized.
To define custom data-binding properties for an image field
You can use binding
options to build a form that captures data for enterprise infrastructures
and/or use an external data source to populate a form at run time.
Select the image field.
Enable the form to connect to the data source when the form
Bind the field to its corresponding data node. For information
about how to bind objects to a data source, see “Binding fields to a data source.