Table 2: Summary of abnormality types, features and claimed experimental results.

Paper Pathology Feature Experiment results Bleeding Polyp Tumor Ulcer Color Texture Shape Image count Sensitivity Specificity Chen et al. [3] √       √     1,857,657 71.54% N/A Lau and Correia [6] √       √     1,705 88.30% N/A Liu and Yuan [7] √       √     800 99.73% 98.89% Giritharan et al. [8] √       √     275,000 83.1% 93.6% Penna et al. [9] √       √     1,111 92% 88% Karargyris and Bourbakis [10] √           √ N/A N/A N/A Li and Meng [11, 12] √     √   √   200 92.6% 91% Li and Meng [13, 14]       √   √   100 93.28% 91.46% Karargyris and Bourbakis [15]       √     √ 50 100% 67.5% Iakovidis et al. [16]   √       √   4,000 87.5% N/A Karargyris and Bourbakis [17]   √         √ 50 75% 73.3% Li et al. [18]   √         √ 300 89.8% 82.5% Barbosa et al. [19]     √     √   192 98.7% 96.6% Barbosa et al. [20]     √     √   600 97.4% 97.5% Karkanis et al. [21]     √     √   N/A N/A N/A Li and Meng [22]     √     √   300 97.33% 96%

Sensitivity = Number of True Postives/(Number of True Postives + Number of False Negatives). Sensitivity of 100% means no positives are incorrectly marked as negative. In other words, the test recognizes all positives. Specificity = Number of True Negatives/(Number of True Negatives + Number of False Postives). Specificity of 100% means no negatives are incorrectly marked as positive. In other words, the test recognizes all negatives. N/A: data is not available.