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Droplets

ORI’s Upgraded "Forensic Droplets" for the quick examination of scientific images

Droplets are small "desktop" applications in Adobe Photoshop®, that automatically process files dragged onto their icon. Droplets are created by recording and saving sequences of steps in the Actions Palette. Each Droplet can be copied to the desktop, to create a near seamless interface for quickly examining the details of a scientific image in Photoshop while reading the publication in the FULL TEXT (html) form or in the PDF form in an Internet Browser.

USE: From within the Internet Browser, drag and drop the fully expanded image over the icon of the saved Droplet, and the latter will open Photoshop and complete a sequence of pre-recorded actions. If Photoshop is already running in the background, 'runtime' will appear almost instantaneous (i.e., in the absence of dialogue and setting options). However, ORI's Prototype Droplets were created for educational purposes, with relevant dialogue and settings features active, to permit user experimentation. After a Droplet has completed its action, the steps can be reviewed by going to the History Palette and "sliding" back and forth through the steps.

The user can create new droplets from the provided Actions.

FORENSIC DROPLETS (CS2 and newer)

Unzip the files below your computer's Desktop and then follow the directions above

Title Description Format Download
Download Full Set Download all Forensic Droplets listed below in a single zip file. .zip Download File
Features in Dark or Light Areas: This Droplet simply applies Histogram Equalization, which may reveal areas of erasure in dark areas, or areas of whitening in bright areas. The process is most effective if the contrasting borders can be first cropped from the image, and restricting the "set-up" area to an area where the range of intensities is reduced. Then selecting "equalize entire image based on selected area" option will force an overexpansion of the new histogram to create a too highly contrasted image, but one that may reveal small boundaries where splicing occurs. Inconsistencies revealed by this process should be explored in more detail with the "Forensic Gradient Map." .atn
(zipped)
Download File
Forensic Gradient Map: This Droplet combines several features of the two early droplets ("Colorise Shapes & Details" and "Solarize Margins & Edges.") Forensic details in the background on in fine structure surrounding the features in question may be used to visualize evidence to assess whether two features are the same. This droplet uses a non-linear contrast adjust and amplify differences False coloring facilitates detection of small differences in gray shades that would be otherwise imperceptible. The principles are demonstrated in an attached PowerPoint slide. .atn
(zipped)
Download File
Useful Gradients A: These are a series of LookUp Tables that were created for the Forensic Gradient Map: A Look Up Table (LUT) that has multiple cycles for contrast or color are best suited for an area in images that has shallow contrast and/or low detail. Details in images with which contrast or steep spatial gradients (small features) will be better revealed using LUT's with fewer cycles in contrast or color. See the "Comments: in the READ ME file #1 for further advice about their use. .atn
(zipped)
Download File

 

DROPLETS FOR COMPARING TWO IMAGES:

The following set of Droplet compare two images, and so they require that Photoshop first be running with the both images already open:

Color Coded Overlay: Any Droplets in this category overlays two images, and color codes each so that individual features in the overlap can be linked back to their respective image.

To use, drag and drop the first image into the Photoshop application. Next, drag and drop the second image onto the icon of the Droplet, and the sequence will proceed.

The specific color scheme may vary, but in general regions where dark features overlap will appear RED, and areas of overlapping background will appear CYAN. Features unique to one or the other image will be WHITE or BLACK. If the same object is common to both images it 1) must be RED and 2) must have a uniform boundary of either BLACK or WHITE. The image can be resized and reoriented using "Free Transform" in the Edit Menu to test alignment of the images. The method of comparison is completely analogous to the widely used colocalization technique that is a widely used and accepted method in cell biology.

The color-coding for features in the overlapped image that are not common to both sources may vary depending on the type of image. In this case, a useful technique for identifying the source of any features is to pre-label each respective image with a large letter or number in the same relative location, such as the upper left corner. The color of the non-overlapping portion of the respective labels will then serve to identify the origin of any specific feature in question.

The specific Droplets for Image Overlay are as follows:

Title Description Format Download
Download All Files Download all Forensic Droplets files listed below in a single zip file. .zip Download File
Overlay Blots - Light Background This Droplet overlay blots of normal contrast and provides an overlay with a white background (the main reason was to save "ink" on printout!). Intermediate decision step includes the nonlinear adjustments in contrast for each image. .atn
(zipped)
Download File
Level & Overlay Blots - White Background This Droplet is designed to overlays blots that are dark or overexposed, by first making adjustments through first level in contrast in each image. Like before, the resultant overlay results in a white background as above. .atn
(zipped)
Download File
Level & Overlay Dark Blots This Droplet levels dark blots, but reverts to creates the original black background used in original forensic droplets .atn
(zipped)
Download File
Overlay Figures - White Background This Droplet is designed to overlays blots that are dark or overexposed, by first making adjustments through first level in contrast in each image. Like before, the resultant overlay results in a white background as above. .atn
(zipped)
Download File
READ ME 1 FILE The Read Me file includes a Comments Section contains general advice for the use of the Gradient Map to visualize subtle features in images, and an explanation for the basis for why it is effected. In addition, a section on Interpretation gives a very brief overview of what to make of the results. .doc Download File
READ ME 2 FILE Means to Inspection and Extract Images, with Tips for Searching. .docx Download File
READ ME 3 FILE Forensic Tips (Alternative to some of the content in README 2) .doc Download File
Gradient Map Demonstration Slide This slide illustrates the principles of the visualizations using the gradient map. .ppt Download File
Useful Gradients Look Up Tables for the Gradient Map .grd
(zipped)
Download File

Comments are Welcome:
Simply email ORI using "Forensic Droplets" in the subject line.


Source URL: https://ori.hhs.gov/droplets