House Floors, Imaging, and Modelling with Tablet Computers

Over the past two weeks, we have exposed the house floors in both the Little Proulx House and the 1 X 5 m test trench in the WilliamKaulehelehe House.  In both cases, the floors contained evidence of burning consistent with the destruction of both houses by the US Army ca. 1860.  The floors are rich with Hudson’s Bay Company-era artifacts, including beads, buttons, ceramics, vessel glass, window glass, square nails and many other items. There is a very distinctive burnt surface in the eastern half of the Kaulehelehe House site with some evidence of north-south running wooden planks which may indicate a wooden floor that burnt in place or a fallen wall.  In the midst of this rich deposit of artifacts and charred wood and charcoal, a door pintle was found.  This object is of particular importance as it is reported that the U.S. Army removed the windows and door from the Kaulehelehe House prior to torching it on March 20, 1860.  This door pintle and the associated burn layer adjacent to it may be a direct link to the destruction of the house site and the eviction of the Native Hawaiian preacher.

The William Kaulehelehe House site showing the hearth and some preserved planks and charcoal staining.  A door pintle is located in the northern portion of the image.  A water screen sample was previously removed from the southwest corner of the unit and the floor around the hearth has already been excavated.

We had two groups who came to tour the site from the Ke Kukui Foundation.  It was amazing to share these finds with people who have such an interest in Hawaiian heritage and the story of the Hawaiian diaspora.

Dr. Bob Cromwell and I interpret to the Ke Kukui Foundation tour at the Little Prouxl House Site. 

Following the E'se'get Archaeology Project, I decided to capture the hearth using the Autodesk 123D Capture program with my iphone.  As we do not have a 4G connection or wireless access in the field for the iPads, I did not use the tablets for this experiment.  I was quite surprised at the resolution and ease with which 3-D models could be generated in the field.  I took 36 photos of the feature from different angles and submitted them to the Autodesk server that crunched the data in about 15 minutes.  The results were later converted into a video animation on my lap top that I have posted on my University YouTube channel:

YouTube animation of the William Kaulehelehe House Site Hearth (Feature 406)

 As we use the tablet computers, we have begun to discuss improvements to field recording that are facilitated by the concentration of many tools associated with one device.  An obvious improvement would be to take a photograph of the floor of each level as a background for drawing things like rocks, sediment variation, feature boundaries, etc.  Without tablet computers, this is difficult as there are generally only a few cameras on each project.  As each tablet contains a high-resolution camera, it is much easier to collect photographic data on the floor plans (and profiles).  Both the iDraw and pdf Expert apps can import images, although the iDraw app is more sophisticated.  

One issue has been with correcting the distortion caused by cameras that were not placed directly above the floor.  The use of photo-processing apps that remove the distortion (orthorectify the photo) and create a planimetric view may allow a resolution to this problem.  There are a variety of apps available that straighten and flatten images, including programs designed to capture the text and images from whiteboards.  We will be experimenting with some of these apps to improve the capturing of these data.  Simplifying the drawing process may help to streamline the archaeological recovery of data and allow for more sophisticated data to be collected and processed directly in the field. 

Once the distortion is removed, then the picture can be cropped to the size of the unit floor (usually 1 x 1 m) and then dropped into and registered to the image space on the recording form.  Annotations can be placed on top of the image.  For those annotations that were placed prior to the completion of the plan, a translucent image can be generated that will show the earlier details underneath the image.  Theoretically this will free up time drawing things like rocks that are obvious in images, while leaving the ability to annotate those aspects of the floor plan that are not as easy to discriminate with photography.