Using Adobe Photoshop for Research and Profit

Photoshop CS3 Extended is a true analytical powerhouse. Beyond typical photo editing, airbrushing, or digital art tweaks, it features a wide selection of advanced image measurement tools.

Simple image processing can be both fun and easy. In fact, various books have even been published on the use of Photoshop in forensic science!

I recently watched a tutorial on using Photoshop for Biomedical research and general research workflows. The training included step-by-step guides for everything from analyzing protein expression in microarrays to mapping tissue penetration data. Since most readers aren’t biomedical researchers, let’s explore how you can use these measurement features for creative, real-world projects.

Below is a breakdown of Photoshop’s best measurement applications. This guide assumes you already know how to open images, manage layers, and make basic selections.

1. Measuring Angles and Lean

Want to compare a tipping Jenga tower to the actual Leaning Tower of Pisa? You can calculate precise angles instantly using these steps:

• Select the Ruler Tool and drag it directly along the sloped edge of the object.
• Read the exact angle off the “A value” in the Options toolbar at the top of your screen.
• Alternatively, select Record Measurements from the Analysis drop-down menu, then check the “Angle” column in the Measurements Log.

Using this tool, the real Leaning Tower of Pisa clocks in at about 86.03°. Try it out on your own structures to see how accurate your lean really is!

2. Calculating Shape Circularity

According to Adobe, circularity is calculated using the formula: 4pi(area/perimeter^2). A value of 1.0 indicates a flawless circle. As the value drops toward 0.0, it reveals an increasingly elongated polygon shape.

You can use this formula to mathematically track the moon’s transition through its lunar cycle:

1. Use the Magic Wand Tool to select the dark emptiness of space surrounding the moon.
2. Invert your selection by navigating to Select > Inverse.
3. Use the Rectangular Marquee Tool to subtract any other objects or moons you don’t want to measure.
4. Go to Analysis > Record Observations and view the “Circularity” data heading within your Measurement Log.

Because there are roughly 30 days between full moons, you can use a digital camera and Photoshop to determine the exact day of the month based entirely on the moon’s circularity.

3. Counting Objects Automatically

Instead of counting items in a photo manually, let Photoshop do the heavy lifting. This works perfectly for items like candies in a bowl:

1. Use the Magic Wand Tool to select a single item (like a green M&M).
2. Go to the Select menu and click Similar to expand your selection across the entire image. You can adjust the tool’s tolerance if it misses some items.
3. Navigate to Analysis > Record Observations.
4. Check the “Count” heading in the Measurement Log. Look there and you can see exactly how many distinct items are highlighted.

In a manual test count of 74 candies, Photoshop estimated 70. You can use this rapid method to count stars in the sky, freckles, or any clearly separated objects.

4. Tracking Teeth Whitening Data

Most cosmetic product reviews are just promotional spam. If you want objective, quantitative data on whether a hydrogen peroxide gel is actually removing stains from your teeth, track it yourself:

1. Import a close-up photo of your smile into Photoshop.
2. Use the Rectangular Marquee Tool to select a uniform color sample from your teeth.
3. Go to Analysis > Record Measurements.
4. Scroll to the Mean Gray Value column (which scores brightness on a scale from 0 to 255).
5. Repeat this process at regular intervals during your treatment to graph your whitening progress over time.

5. Scaling and Calculating True Heights

If you have a photo of a person standing next to an item of a known size, you can calculate their exact height. For example, if someone is holding a book that you know is exactly 9.2 inches tall, follow this workflow:

1. Open the Analysis menu and choose Set Measurement Scale > Custom.
2. Click and drag the Ruler Tool from the top to the bottom edge of the known reference object (the book).
3. Enter the real-world dimension (9.2 inches) into the dialog box. All subsequent measurements will now scale automatically to this reference point.
4. Use the Ruler Tool to measure the individual from head to toe.

6. Estimating Regional Populations

By pairing density maps with a metric called Integrated Density (the product of an area and its mean gray value), you can estimate vast populations across an entire continent. Here is a simplified workflow:

• Isolate the target geographic borders on a clean map.
• Calibrate your map pixel scale to kilometers using a reference world map.
• Convert your color-coded density map accurately into grayscale.
• Select the region and click Analysis > Record Measurements.

Applying this method to a map of Africa calculates the total land area at roughly 30.11 million square kilometers—exceptionally close to the actual value of 30 million km².

By scaling the resulting mean gray value against the known maximum animal density per square kilometer, you can accurately estimate total populations across massive geographic zones.

Conclusion

Photoshop is an incredibly versatile tool that goes far beyond simple graphic design. Its built-in measurement engine turns standard images into rich, accessible datasets. What patterns or objects are you planning to measure next?

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