1. A method comprising: applying a filter having a stroke width constraint and a stroke color constraint to an image to generate a first map based on the stroke width constraint and a second map based on the stroke color constraint; applying a first classifier to both the first map and the second map to generate a third map identifying a component of a text in the image; applying a second classifier to the third map to generate a fourth map identifying a text line of the text in the image, wherein the second classifier comprises a Text Covariance Descriptor (TCD) algorithm for text lines, the TCD algorithm configured to: compute a first covariance matrix for correlated features of components between heuristic and geometric properties of the first map and the second map, compute a second covariance matrix for correlation of statistical features among the components, generate a feature vector based on the first and second covariance matrices, a normalized number of components in a text-line, and a mean confidence score of the third map, and generate a confidence score of the fourth map for each text-line candidate from the feature vector; and thresholding the fourth map to identify text regions in the image.