Tiruvalangadu Plates in 3D

The assessment required us to choose a topic and demonstrate our understanding of methods and techniques used in the development of Cultural Heritage applications, by selecting advanced image synthesis, animation and interactive techniques appropriate for achieving the chosen Cultural Heritage topic.

I chose to build the Tamil Cooper-plates of Tiruvalangadu in 3D, using the photo scans of the plates captured in“South Indian Inscriptions vol.3; pt.3 and pt.4”. I used Autodesk Maya and Vray (3D rendering), Photoshop(Image enhancement)

Tiruvalangadu plates were discovered and translated by India’s first epigraphist Rai Bahadur V. Venkayya. Unearthed in 1905, Tiruvalangadu copper plates are found in the village of Tiruvalangadu in the Tiruvallur District of Tamilnadu, India

This set of plates contains a set of 31 plates. It is said to have been inscribed in the year 1016-1017 AD. The first 1-9 plates are inscribed in Sanskrit, and the rest 11-31 plates are etched in Tamil. In the middle 10th detached plate, the first side is inscribed in Sanskrit and 2nd side is inscribed in Tamil characters. 

My Plan for creating the artefact was to use the photo scans and enhance the image so that it is used as a normal map which then can be assigned to the mesh in Maya and rendered. My goal was to create maximum contrast between the background colour and the inscriptions without losing the inscription text, such that the image would provide a good normal map. 

The challenge of this project was the photo scans were the limited resource available to me to build the artefact. Faced with this limitation of accessibility and lack of resources, I decided to make use of Photoshop for the image enhancement of the existing photo scans. 

Since I had to work on 31 images of the plates, I decided to set up a framework of image adjustments and worked in layers. It was a trial-and-error practice to set up the framework, but the key elements function that I used was the:

Auto tone and Auto contrast (To Correct the tone and contrast of the image)

Invert (To invert the black and white colours)

Brightness/Contrast(To build the first pass of contrast between the background and the characters),

Shadow/Highlights (To remove or adjust the mid-tones present in the image),

Back/White Adjustment( To change any RGB channel in the image to white)

Level and Exposure(To increase the contrast of the image)

The order of the task might differ from plate to plate, but key functions were constant for all plates. 

Sanskrit Plates

Auto tone and Auto contrast-Invert- Brightness/Contrast-Invert-Brightness and Contrast- Black and White

Shadow/Highlights - Level and Exposure

Tamil Plates

Auto Tone and Auto Contrast - Brightness/Contrast - Black and White - Invert

Shadow/Highlights - Level and Exposure

After getting the desired contrast of the plate, I created a normal map for every single plate. I tried to use a Height map as well, but the resulting image was compromising the text of the plate. I settled for the normal map instead.

Result Renders

Sanskrit Plates

10th Detached Plate

Tamil Plate

Final artefact 

Self-reflection and Acknowledgements

While I was able to enhance the images well enough for 3D visualization and preserve most of the images, the need to achieve the most contrast out of the plate sometimes rounded and thickened some of the edges. This reduces the clarity of the inscription characters. While this can be considered as an attempt at 3D visualization of plate images, more work and improvements must be done if we ought to conserve the artefact appropriately. It is necessary to take high-quality photographs with DSLR cameras along with the correct lighting setup. The use of  Multi-Spectral Imaging (MSI) in this scenario can be the best option for clearing the damaged parts of the text. This project can also be developed by working closely with linguists and language experts who can give guidance for the reconstruction of the damaged characters.

I would like to thank Dr Eike Falk Anderson( Unit Tutor) who made the unit interesting, enjoyable and informative.