Steve Everist brings us the second article in a
series on Adobe Photoshop for latent print examinations.
Latent Adobe Print
Photoshop Series Part 2: Saving Actions
By Steve Everist,
King County Sheriff's Office - Seattle, WA
When actions are created, they are saved as a file with the extension .atn.
These files can be shared with other Photoshop users. On Adobe’s website,
there is an area known as the Studio Exchange where users can share their
custom actions. Although the actions available in the Studio Exchange are
not created for forensic purposes, I will use them as an example of how you
can save and load actions that you share with others through email or from
If you would like to download some of these actions from the Studio Exchange
site, you will have to sign up through Adobe’s website. This will require an
email address and password. If you currently have an Adobe Store username
and password, you will still need to create a new one as the old one does
not work with Adobe Studio 2.0. You can sign up later, when you go to
download an action.
Adobe Studio Exchange can be found at
http://share.studio.adobe.com/. Photoshop actions can be found under
the Photoshop Downloads pull down menu.
I’ll select the Image Effects category, which will take me to a page with a
selection of different actions that have been uploaded by different
Photoshop users. After finding an action that I’d like to download, I’ll
click on the download link associated with the action. This will bring me
to the Download Instructions page.
Now I will right-click the
download link and select Save Target As…
I can save the
action in any folder. I have chosen to save it in the Adobe Photoshop
Once finished downloading, I
will close the Download dialog box.
Now I will go into Photoshop
and load the action. To load an action, I will go into the Actions Palette
menu, accessed by clicking on the arrowhead in the upper right hand corner,
and select Load Actions…
The Load dialog box will pop
up where I will select the action that I have downloaded.
The new action will now show
up in the Actions Palette.
This is an example of how to download an action and load it into Photoshop.
The same principles apply to actions sent through email or downloaded
through other sites. They need to be saved to a location where they can be
found and loaded. You can create a separate folder for your actions or save
them into Adobe Photoshop Actions folder.
Lab Color a Action
Now I will create a new action using the Lab Color a channel and the
Auto Contrast function. Adobe Photoshop’s Help menu has information
regarding the Lab color space.
First I will open the image that I will be working with. For creating the
action, I can use any image, but to see the steps as I progress, it is best
to use an image similar to one where I would find the particular action
When I create an action, I must remember to take the Actions Palette out of
Button Mode. (see the Detail 211 for details) On the Actions Palette, I will click on the “Create new
action” icon, which looks like a piece of paper with a folded corner.
The New Action box will pop
up where I can give my action a name, specify the set of actions that I
would like the action put into, assign a function key, and choose a color
for the button for this action. I have chosen to call this action “Lab
Color A – Auto Contrast.” This describes what this action is used for and
what steps it consists of. I put it into the “Forensic Actions” set I
created earlier and I chose green for the button color.
Once the action has been set up, I will click the
“Record” button to start recording the steps for my action.
For this action, I will need to convert to the Lab Color color space. This
is done from Image – Mode – Lab Color.
Now I will click on the
Channels Palette. There are four different channels: Lightness, a, b, and
Lab (a combination of the other three). For this action, I will select the
The ridge detail in the
current image is barely visible, so I will perform the auto contrast
function to make it more visible.
The auto contrast function
makes this particular print visible, although the ridges are light on a dark
background. This is done from Image – Adjustments – Auto Contrast.
The light ridges can be
converted to dark by using Image – Adjustments – Invert. You may not want
to record this step, since it will perform this function on all images this
action is used on.
Although the image will appear to be in grayscale at this point, it is still
in Lab color. I will need to convert it to Grayscale. This is done from
Image – Mode – Grayscale.
The Discard other channels
window will pop up. I select OK to discard all of the channels except for
the selected a channel, and convert the image to grayscale.
Now I have finished recording the steps for this action. I will click on
the “Stop playing/recording” icon at the bottom of the Actions Palette.
This icon is shaped like a square.
I have now created an action to use on a variety of
different images to clarify the detail in the print. The new action can now
be found in the Actions Palette for use on different images. After using
this action, the image will be in grayscale. I can now perform additional
steps such as levels adjustments and inverting the ridges.
information regarding Lab Color and actions, go to the Photoshop Help window
and do a search for Lab Color or actions.
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