Jun 3, 2014 - Swarachakra for Hindi, Marathi, Gujarati, Kannada, Telugu,. Malayalam, Odia and Punjabi (Gurmukhi) for Android devices. Categories and ...
Swarachakra Keyboard for Indic Scripts (Tutorial) Manjiri Joshi, Anirudha N.Joshi, Nagraj Emmadi, Nirav Malsattar Indian Institute of Technology, Bombay, India {manjirij;anirudha}@iitb.ac.in; {nagrajmumba;niravpmalsatter}@gmail.com
ABSTRACT Swarachakra is a text input method developed for Indic scripts on touch-screen devices. Swarachakra uses a logically ordered design based on the structure of Indic scripts. Swarachakra displays the consonants sequenced according to the logical structure of Indic scripts, phonetically grouped and arranged in a grid similar to those found in most school textbooks. Currently we have launched Swarachakra for Hindi, Marathi, Gujarati, Kannada, Telugu, Malayalam, Odia and Punjabi (Gurmukhi) for Android devices.
Categories and Subject Descriptors H.5.2 User Interfaces
General Terms Design, Human factors
Keywords Swarachakra, Virtual Keyboard, Indic scripts, Text input
1. INTRODUCTION Most keyboards are designed for long-term use. In order to optimise performance in the long term, the design of keyboards is often based on frequencies of the characters in the language. Keyboards based on logical structure of the script (e.g. the alphabetical order) were not found to be effective for Latin-based scripts [1, 4]. From our evaluations [2,3] we found that logically ordered keyboards for Devanagari script perform better for novice users.
2. DESCRIPTIONS Some of the challenges in text-input in Indic scripts have been addressed by Swarachakra. Text input in Indic scripts often involves typing a combination of a consonant and a vowel (C + V), for example ह + ि◌ = ह. In Swarachakra when a consonant is pressed a “chakra” (circle) appears around it, which gives a preview of the possible character combinations. One of these can be selected with a slide of the stylus or finger (figure 1).
Figure 1. The basic layout of Swarachakra Hindi keyboard with one of the chakras showing C+V combinations.
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Typing conjuncts like , थ, य is another challenge in Indic scripts. After selecting a consonant and a halant (C + halant, e.g. स + ◌्) Swarachakra shows a preview of all possible combinations of conjuncts (figures 2 and 3).
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MOBILESoft’14, June 2–3, 2014, Hyderabad, India ACM 978-1-4503-2878-4/14/06 http://dx.doi.org/10.1145/2593902.2593905
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Independent vowels (अ, आ, इ, ई, उ, ऊ, ए, ऐ, ओ, औ) and the less used vowels and diacritics (ऽ, ऑ, ◌ृ, ऋ, ◌ॄ, ॠ, ◌ॆ, ◌ॊ, ◌ॅ, ◌ॉ) are available on separate keys near the bottom of the keyboard. Numerals, symbols and rarely used characters appear on a shift.
3. CURRENT STATUS Swarachakra has been extended to eight languages – Hindi, Marathi, Gujarati, Telugu, Kannada, Malayalam, Odia and Punjabi. From June 2013 to March 2014, we have had 24,000+ downloads in these languages and currently Swarachakra is downloaded 200 times a day (figure 5). Figure 2. Typing a C+ halant combination
Figure 3. Swarachakra shows a preview of all possible conjuncts when a halant is selected. Shown here is a preview after स + ◌् is selected.
Figure 5. Total Swarachakra downloads.
Swarachakra allows typing words with rafar (थ) or a rashtrachinha () using the modal keys from the right-most bottom keys (figure 4). When one of these modal keys is selected, all the keys show a preview.
4. ACKNOWLEDGMENTS Part of development of Swarachakra was supported by grants from Nokia and Department of Information Technology, Government of India.
5. REFERENCES [1] Gong, J., Tarasewich, P.: Alphabetically constrained keypad designs for text entry on mobile devices. In : CHI, Portland (2005) [2] Joshi, A., Dalvi, G, Joshi, M., Rashinkar, P., Sarangdhar, A.: Design and Evaluation of Devanagari Virtual Keyboards for Touch Screen Mobile Phones. (2011) [3] Kumar, A., Shah, Hemruchi, Joshi, A.: Saral: Devanagari Text input system in Mobile phones. (2009) [4] Norman, D., Fisher, D.: Why Alphabetic Keyboards Are Not Easy to Use: Keyboard Layout Doesn't Much Matter. Human Factors 24(5), 509-519 (1982)
Figure 4. The preview after selecting the rashtrachinha.
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