OceanView is the flagship software program for use with Ocean Optics spectrometers. Beyond simple data visualization, OceanView allows you to generate, customize and save spectroscopy projects using its Schematic View function. Saved projects can then be reloaded or shared with others. The Schematic View presents the data processing steps in a diagram format with icons representing the different devices and processing steps in your project. In the Schematic, you can view and manipulate the flow of data from your spectrometer through each of your processing steps. Data flow is represented by the use of arrows that connect different nodes. The nodes represent points where data is processed or manipulated.
In this project, we measured the reflected color of samples from a Pantone® Formula Guide and calculated the color difference (delta E) of the samples as compared to a reference color standard. Using spectroscopy to measure color difference eliminates errors associated with the limits of human perception of color and provides a more quantitative assessment of color consistency.
About OceanView Schematic View
The Schematic View provides you with all of the functionality of the OceanView graph view, plus additional capabilities to customize your spectroscopy measurements:
- More than 70 algorithm nodes enabling a range of math functions for basic to advanced calculations
- Subrange node to specify a subset of the spectrum or a single wavelength
- Interpolation of spectral data to output data at consistent, evenly space intervals
- Scalar view for monitoring a single value such as TEC temperature or an integral or average over a specified wavelength range
- Ability to preview spectra in graphs at every step in your process
Create, configure and connect schematic nodes to read data from devices, to transform and combine that data through a library of built-in spectroscopic functions, and then to output the results to visual graphs and Microsoft Excel-ready CSV files.
By visualizing all the processing steps of the experiment in the Schematic View, students have an opportunity to develop a deeper understanding of the measurement technique and to customize data processing for their specific application.
This project was created to calculate the color difference -- delta E in the L*a*b* color space -- of Pantone color guide samples compared with a color reference. To make the measurements we used an STS-VIS spectrometer (350-800 nm), bluLoop LED-based light source (400-700 nm) and reflection probe. The color reference was one of the color guide samples.
[featured]Please note that our bluLoop, the multi-LED light source, has been discontinued since March 2016. Please choose an alternative light source. For customers looking for an LED product we offer warm and cold white versions of the LLS. For customers looking for a visible source, our HL-2000 series are always a popular choice.[/featured]
Delta E is used to quantify the difference between two colors. A delta E (dE) less than or equal to 1.0 indicates that the human eye will perceive two colors as the same. As the dE increases above 1.0, the perceived difference in color increases. The calculation of delta E takes a subjective comparison of color and provides a quantitative value indicating how different the colors look to the human eye. Delta E values are used in a wide range of quality assurance applications to ensure that final products look the same to the user. In some cases, depending on the application, less rigorous dE limits are set where the perception of slight differences in color is acceptable.
In this project, we calculated the L*a*b* color difference using reflected color measurements of a sample compared to the reflected color of a user-selected color reference (one of the Pantone guide samples). The user can easily update the color reference reflection spectrum at any time during the measurements to calculate dE relative to a different color reference.
Project Import Procedure
Import the project into OceanView by going to File| Share project| Import. OceanView will guide you through the steps necessary to swap the spectrometer you are using into the project including allowing you to measure new reference and background spectra and capturing an updated color reference spectrum for your color standard.
Once the project is loaded, there are a few more steps required before you can start making your delta E measurements. First, you will need to optimize your acquisition parameters using a reflectance standard – a WS-1 or other diffuse reflectance standard are good options -- and then update the reference spectrum for your reflection measurement by clicking the yellow light bulb in either of the Reflection views. The yellow light bulb updates the spectrum in the Ref node on the Schematic.
Next, block light from getting into the spectrometer with a shutter or by pointing the probe into a dark location. Then click the gray light bulb in either of the Reflection views to update the dark spectrum. The gray light bulb updates the spectrum in the Background node on the Schematic.
After you have updated your Reference and Background spectra, you will need to update the spectrum for your Reference Color using the green button with the black arrow in the Reference Color Reflection view. The Reference Color reflection spectrum is the reflected color spectrum for which you want to compare all other samples – your color reference. The green button with the black arrow updates the spectrum in the Color Standard Reference node on the Schematic. Once you have updated these spectra, you are ready to measure delta E.
User Tip: A simple place to start your project is to use the Reflected Color wizard in OceanView, then adjust the nodes within Schematic View to meet your requirements.
- Download your OceanView 10-day free trial
- Learn more about delta E in the application note Controlling the Color Consistency of Beverages using Spectral Sensing
- View the Color Measurement overview in Measurement Techniques