An approach to color modification for artifact photo editing.

Author: Cesar Najarro | B.A. | University at Buffalo

Having photographed numerous artifacts, Professor Funk and I noted that the photos contained a considerable amount of blurriness reducing the focus ability to transmit finer details, and so she asked me to find a technique to enhance the photo quality. With this in mind, this post will be focusing on why I chose to edit the artifact photos in the way I did. In order to do so I first identified the key steps I take when editing photos, namely increasing the photo contrast and sharpening the borders of different colored pixels.

Now, when looking at each photo I had to decide a way to make the colors richer, as I personally believe this gives the color a bolder aspect and when trying to improve the quality of a photo this is a significant factor as it helps increase contrast (consequently blurriness is reduced). My research into Color Theory backs up this idea; referred to as Chroma[1], the notion of darker colors being more intense is supported upon examination of the color wheel, where duller colors are more towards the center and darker colors on the outer rim, as they are more intense.

Image 1

With this in mind, the modification I made to photos involved using the Curves feature of GIMP, as this gave me the most control over the extent to which I could modify the photo (while Contrast does also do the same, the resulting edit is not as sharp as when modifying the colors using Curves). The way in which I modified the curve was to simply drag the curve along the horizontal axis, because by making the line more vertical the colors became bolder (however this had to be done with some restraint in order to retain the image’s realism; a ratio I found to work was 20;9 (x and y axis respectively).

Image 2

Image 3
Example of curve modification and resulting image. [3]
Image 4
Before and after of artifact UA2014-64-0510 from KIS-050 on Kiska Island, Alaska.

 

[1] http://www.axaltacs.com/content/dam/NA/HQ/Public/Axalta/Documents/Brochures/AX-Color-Theory.pdf

[2] http://www.certapro.com/uploadedImages/Corporate/Content/Blog_Images/52143744.jpg?n=8232

[3] https://docs.gimp.org/en/gimp-tool-curves.html

Learning about archaeology through lab work

Author: Cesar Najarro | Senior | University at Buffalo | Feb. 15, 2016

My name is Cesar Najarro and I am currently a senior at the University at Buffalo and have been working in the archeology lab with Dr. Funk for about two months now. The focus of our research revolves around a series of islands located just off the coast of Alaska called the Aleutian Islands. These islands were inhabited by a semi-nomadic people named the Aleuts (also know as the Unangan). These people lived off land and sea resources, particularly the marine fauna available to them at different times throughout the year. Their prehistoric sites throughout the islands include massive deposits of animal remains resulting from generations of hunting and eating and disposal habits. These remains allow us to understand several varying factors about the environment and the impact humans had on it.

My first assignment in the lab was to categorize and sort the material collected in 1/8th inch screen based on the characteristics of the various fragments in the samples. Among these fragments were fishbone, bird and mammal bones, charcoal and sea urchin skeletal parts. All of these remains result from Aleut activities and thus give insight as to how they shaped their environment. In particular the sea urchins were of great importance because of their sensitivity to any type of environmental change, thus making them excellent markers for different time periods, as the size of their remains change by noticeable amounts. Although sorting was not the most exciting task in particular, it did give me a new found appreciation for the patience and dedication archeologists must have in order to properly categorize their findings while simultaneously looking for patterns within the fossil record in order to make an outline as to how the environment changed and what possible factors influenced said change.

My second and as of now current task revolves around capturing and processing digital images of bone artifacts made by the Aleuts, such as fishhooks. This I find much more interesting because it caters to one of my own hobbies (photography) as well allowing me to further develop my skills with image processing software. Capturing the  photos is straight forward, there is a small set up we have to do before hand in order to best capture the details of the artifact; factors such as light, angle and even movement of the camera must be accounted for in order to capture the best possible image of the artifact. Once this is done, I process the photo using GIMP (GNU manipulation software; https://www.gimp.org). I edit the images in order to refine and highlight certain aspects of the artifacts, such as carvings and breaks. This all serves to give insight into the culture of the Aleuts and convey the level of sophistication these people had in their ability to craft fine details into their tools, a trait that can be associated with a society with a strong culture and rich history.

Measuring Bird Bones

Author: Ariel Taivalkoski

While it has become more common to identify the bird bones from archaeological sites to family, it is rare to have a bird bone assemblage as large as that from the Rat Islands Project site KIS-050 test excavation. The midden context of this Kiska Island site has preserved the bird bones in excellent condition. We have over 5,000 bird bones, many of which are whole. It was initially daunting to organize the data collection for this assemblage and our analysis spreadsheet went through several iterations before I was able to create a database that allowed us to collect the most useful information while still allowing us to finish the analysis of this collection within a timely manner.

During one of the revisions of our spreadsheet, I decided that I would need to begin measuring our bones, following standards in Gilbert (1996) and Driesch (1976) that aid in species identification. My primary goal for recording these measurements was to help us quickly differentiate between the large numbers of Alcids, which range greatly in size, that were present at the site. Additionally, this will help us to conduct our overall species identifications in a timelier manner.

This revision came after I analyzed 15 level assemblages to family. Dr. Funk and I have spent a couple days recently revisiting the identified elements to record these standard measurements. This process has allowed us to expand our data set, as well as served to double-check my family level identifications for the first identfications I made.

Ariel Bird Bone

Invertebrates in the midden

Author: C. Funk | Rats Project Lab at UB | July 9, 2015

Thanks to the efforts of twenty or more undergraduate students, graduate students, and researchers at UB and Hamline University our ¼ inch screen bulk samples from the KIS-050 village midden are sorted to component parts. Samples of identified fish, bird, and mammal elements are in the isotope lab at UAF. Mammal bone elements are being identified by the Hamline team, birds by the UB team. Stone tools go to Hamline, bone tools stay here at UB.

Josh is sorting and analyzing the invetebrate assemblage from this bulk sample. The materials are c. 1000 years old.
Josh is sorting and analyzing the invetebrate assemblage from this bulk sample. The materials are c. 1000 years old.

This month the invertebrates from the bulk samples will receive our focused attention. Josh Howard, a graduate student working in the Rats Lab at UB this summer and I are sorting, counting, weighing, and starting to identify the invertebrate assemblage from the ¼ inch bulk sample fraction. We measure whole lantern pyramids (mouth parts) from Strongylocentrous spp. (sea urchins) to track their size over time. Smaller urchins may indicate periods of heavy harvesting and signal community shifts in the local intertidal zone. Limpet size shifts may similarly signal ecological changes, but most of the limpets are fractured and impossible to measure – their little hat tops, the apex portions, are separated from their wide brims.

Periwinkles and other gastropods, mussels, and chitons live in the modern rocky intertidal zone near the archaeological site, but they are poorly represented in the archaeological assemblages. We count the hinge fragments of mussels and the whorls of gastropods to learn how many are present in a sample. The numbers are variable, but low for each bulk sample – less even than one serving of bouillabaisse or Portuguese caldeirada de peixe might have in it. We’d be happy to count chiton plates, if only they were present in the prehistoric occupation debris of KIS-050. We thought they should be present, since our team ecologist saw so many in the modern intertidal zone.

Archaeologists in the Aleutian Islands tend to think of prehistoric sites and reefs as paired – reefs can be rich resource areas. But as our work continues to demonstrate, prehistoric Aleut use of these resources was complex. The details of which invertebrates were harvested, where they were eaten, and how people disposed of them remain obscure to us. Measuring invertebrate abundance, size, and community parameters will tell us more about the circumstances of Aleut choice – what species were even available to eat in the dynamic intertidal environment?

The sorted shellfish, awaiting further analyses.
The sorted shellfish, awaiting further analyses.

Sorting Midden, Analyzing Bones

Author: C. Funk | UB Rats Project Lab | May 29

Our bins of unsorted midden and unanalyzed bird bones are emptier every day as we work through our sorting and analyses. Darren Poltorak just spent three months sorting 1/4″ screen bulk samples  – we sent the fish he sorted to Megan Partlow of Central Washington University for analysis. Her data will be posted on our results page soon.

Darren sorting fish from the 1/4" bulk samples.
Darren sorting fish from the 1/4″ bulk samples.

I’m weighing, counting, and measuring the shellfish from the bulks Darren sorted. Soon Josh Howard will be sorting the 1/8″ screen bulk samples. He’ll be measuring many sea urchin mouth elements so that we can look for changes in sea urchin body size over the more than 2,000 years people harvested them from the Corvie Bay intertidal zone. Ariel Taivalkoski and I are working to identify our more than 5,000 bird bones. So far she (with a little help from me!) has identified 1,700 bones to avian family. We are seeing interesting shifts in the types of birds present over time and in differentl behavioral contexts.

Ariel entering avian faunal analysis data.
Ariel entering avian faunal analysis data.

Research posters at the SAA meeting.

Author: C. Funk | University at Buffalo | April 13, 2015

We are heading to the 80th Annual Meeting of the Society for American Archaeoloy in San Francisco this week. We are scheduled to present two research poster sessions on Thursday.

The first poster on Thursday morning is presented by B. Hornbeck. She and her co-authors focus on the mound groups we mapped during our Summer 2014 field season.

Hornbeck et al SAA 2015 Poster Final

The second poster, Thursday evening, is presented by Caroline Funk. The poster is a summary of the full research team efforts so far. The image below will expand if you click on it.

Funk et al SAA 2015 Poster Draft Final

Tissue Sample Preparation Video

Author: C. Funk | University at Buffalo | March 9, 2015

Dr. Nicole Misarti filmed lab assistant Kelsey Saylor while she prepared a freeze-dried mussel sample for stable isotope analysis.

Watch the youtube video: http://youtu.be/KzGRvNKlcfE

Learn more in Dr. Misarti’s earlier blog post about stable isotope analysis.

Food Web Model for Vega Bay, Kiska Island

Authors: Caroline Funk and Spencer A. Wood | February 20, 2015

Our team marine biologist, Dr. Spencer Wood, is building food webs as part of his research on marine communities. Spencer spent the 2014 field season in the intertidal zones near prehistoric Aleut village sites. His gear and clothes weighed more than he did; most days he went out into the rocky reefs wearing five or six layers of long underwear, fuzzies, and raingear – topped by warm hats and a PFD. He recorded the presence of species and counted them using formal data-collection procedures. Spencer also collected small tissue samples from some of the species, for isotope analysis in Dr. Nicole Misarti’s lab (see our previous post “Intertidal Foodweb Analysis” and the Wig-L-Bug video coming soon).

Spencer in the intertidal zone.
Dr. Wood sampling the intertidal zone below the 1,200 year old KIS-050 village midden. Image by B. Hoffman 2014.

Back in his office in Seattle, Spencer digitized his field data and combined them with information from an existing database of the known trophic relationships between species – who eats whom in the ocean. By melding observational data from the field with other information on the characteristics of the species that he observed, Spencer is able to create interesting depictions of the ecological communities that show how species are linked together into food webs around ancient village sites.

The Vega Bay Food Web Model

Wood2014_VegaBayFoodWebModel-01

The image here is a visual representation of the food web of the modern Vega Bay intertidal zone. It depicts the species (or taxonomic groups) present, their prey and predators, and the number of relationships among them. The image shows a network of predator-prey interactions. The size of the circle, called the node, indicates the number of links that any given taxon has with other taxa. A large diameter node indicates many connections. Lines curving clockwise from one node to another depict a predator eating its prey. Lines that curve counterclockwise indicate prey are being eaten by a predator.

Look at Bacilariophyta (diatoms) and Detritus (material from dead organisms) in the food web. These nodes are large, which means that they are linked to many other taxa. But, the links to them curve counterclockwise, which means that are being consumed by organisms like zooplankton (Copepods), snails (Littorina), and chitons (Mopalia). Gulls (the Larus node just right of center) have links that curve in both directions, showing that gulls are both a predator and a prey, depending on who they encounter.

Today people do not inhabit the region, so they are absent from the modern food web diagram. In the past, however, prehistoric Aleuts ate a wide variety of plants and animals from the intertidal zone and would be represented in a prehistoric food web as a large node with links to many different prey.

What Can We Learn From Food Webs?

Food webs are useful for understanding and predicting how changes will impact ecological systems. Fish and wildlife managers, for example, use them to estimate potential impacts of fishing and hunting and to set quotas. Other scientists use them to predict how changing temperatures will impact ecosystems. Our team is using the new food webs for Vega Bay and other sites in the Rat Islands to understand whether marine communities function differently today than they did thousands of years ago. Our team is also using information from our archaeological studies to construct food web depictions of ancient intertidal communities, from time periods when people lived in the Rat Islands. Including humans in these large, data-rich food web models allows us to better understand people’s relationships with other species in the marine environment. Soon, we’ll begin including other types of interactions into our networks, beyond just links between predators and their prey. We want to know more about the “non-trophic” roles of people, as culturally motivated resource collectors and members of the ecological community, and how they have impacted and been impacted by the dynamic environment over millennia.

Researching human and environmental intersections in the Aleutian Islands.