Computational Philately

While computers have long been used for philatelic databases, this site focuses on applications involving computational analysis applied to philately. Regarding databases, there are many sites and blogs that discuss and promote the use of software for creating inventories, album pages, and collection valuations. These applications range from do-it-yourself spreadsheets to commercial programs for collectors to create inventories, track valuations, and create album pages.

What I mean by computational philately is the programming of computers to perform relatively technical analyses of stamps. An example would be the technical manipulation of a digital image's data to analyze the color content of the image. Computational applications will often involve mathematical methods used in numerical analysis. While computation is inherent in all software, this focus on more technical applications distinguishes this site. Unless commercialized, these applications are in the realm of custom programming using various computer languages. Many free software development platforms are now available that provide extensive support and facilitate technical programming. For the applications described in this site, I have made extensive use of the Microsoft Visual C and the Netbeans programming platforms.

At this time, I can separate the applications in this site into two groups: color analysis and image analysis. I will expand this list as new content is developed or brought to my attention. The Institute for Analytical Philately (IAP) is a primary resource for new developments in technical philately. The American Revenuer also deserves special mention for their support of the publication of technical research related to revenue stamps. Note, however, that I am not including in this site applications which are already a part of well-established topics such as the analysis of data obtained from spectroscopic instrumentation. My current list of applications is:

Color Analysis

Two researchers active with the IAP in the subject of the color analysis of stamps are John Cibulkis and Tim Lyerla. John has been working to create objective methods for a computer to match real stamp colors from images to a color guide such as Michel Color Guide, while Tim has been using tonal histograms to analyze and compare the color shades of stamps. Recent publications with links are:

Cibulkis, John. 2016. Towards a Stamp-Oriented Color Guide: Objectifying Classification by Color. Proceedings of the Second International Symposium on Analytical Methods in Philately, Itasca, IL, November 2015, John H. Barwis and Thomas Lera, eds., Wilcox Printing and Publishing, Inc., Madrid, IA, pp. 31-40.)



Cibulkis, John. 2016. Resolving the Scanner Dependency in Color Matching. Proceedings of the Second International Symposium on Analytical Methods in Philately, Itasca, IL, November 2015, John H. Barwis and Thomas Lera, eds., Wilcox Printing and Publishing, Inc., Madrid, IA, pp. 41-48.)



Lyerla, Tim. 2016. Shade Verification Using Tonal Histogram Analysis. Proceedings of the Second International Symposium on Analytical Methods in Philately, Itasca, IL, November 2015, John H. Barwis and Thomas Lera, eds., Wilcox Printing and Publishing, Inc., Madrid, IA, pp. 87-94.)



Work that I have done in color analysis includes the "Cancel Extractor," a choice in the menu bar of this site. This application uses a low resolution histogram of RGB color sampled from an image to remove these selected colors from the image. Included for mention here is the program retroReveal, a somewhat related program that applies a large assortment of filters to an image that the user can review for their potential utility. The cancel extractor is explained in:

Mustacich, R. 2016. Seeing Only the Cancel. The American Revenuer, 69(3): 79-82.)


Image Analysis

Two types of image analysis that I have been studying are the analysis of perforations (and other types stamp separation), and the high resolution, subtractive comparison of images. Using inexpensive scanners, it is possible to measure perforation features such as hole sizes and hole spacings to micron-range accuracy. This capability makes the fingerprinting of perforations possible owing to the consistent repetition of microscopic spacing discrepancies in perforation hole spacing resulting from imperfections in perforating equipment. This research is presented in the following publications:

Mustacich, R. 2014. Freak or Fake? A New Fingerprinting Method for Distinguishing between Original and Fraudulent Extra Perforations of 19th Century Revenue Stamps. The American Revenuer, 67(1): 2-19.)




Mustacich, R. 2015. Fake Perforations on 19th Century U.S. Revenue Stamps: A Stroke of Luck. The American Revenuer, 68(4): 90-96.)




Mustacich, Robert V. 2016. Measurements of Stamp Separation Features by Digital Image Analysis. Proceedings of the Second International Symposium on Analytical Methods in Philately, Itasca, IL, November 2015, John H. Barwis and Thomas Lera, eds., Wilcox Printing and Publishing, Inc., Madrid, IA, pp. 73-85.)




The direct digital differencing of high resolution images can be used to directly compare entire images of stamps for microscopic differences arising from plate variations and printing flaws as well as large differences originating from cancels or from the stamps themselves. The possibility of doing this was initially considered unlikely because of expected variability in optical scanning, paper shrinkage differences between stamps, color differences, digital noise, interpolation losses, imperfect image alignments, etc. A combination of scanning protocols and computational methods were found which can limit and correct for these variations to provide direct digital subtractions of one image from another. These approaches go a leap further to compare the relative distortion differences between the individual plate impressions on a printing plate! This research is described in the following article:

Mustacich, Robert V. 2016. Digital Image Differencing of High Resolution Stamp Images. Proceedings of the Second International Symposium on Analytical Methods in Philately, Itasca, IL, November 2015, John H. Barwis and Thomas Lera, eds., Wilcox Printing and Publishing, Inc., Madrid, IA, pp. 57-72.)