## 3 Proposed Method
### Separation of Overlapping Lines  
A novel technique is developed to separate overlapping lines present in the extracted text line segment from vertical stripes. The number of times that the method is applied for the separation of these overlapping lines depends on the number of overlapping lines in the extracted text line. This is obtained using Equations (3)-(6). The technique then determines the region, \(R_{ov}\), where the initial segmentation is to be carried out. Let \(r_{1}\) and \(r_{2}\) be the rows between which the overlapping of lines occurs, which are determined by Equations (7)-(10).  
If \((M_{L_{ht}}>4\times Avg_{c_{ht}})\),  
\[r_{1}=M_{L_{ht}}-\frac{Avg_{c_{ht}}}{2}, \tag{7}\]  
\[r_{2}=M_{L_{ht}}+\frac{Avg_{c_{ht}}}{2}. \tag{8}\]  
Otherwise,  
\[r_{1}=M_{L_{ht}}+\frac{Avg_{c_{ht}}}{2}, \tag{9}\]  
\[r_{2}=M_{L_{ht}}+Avg_{c_{ht}}. \tag{10}\]  
The reason for overlapping lines is the presence of ascenders and descenders in the language. The ascenders and descenders will be present in the region between \(r_{1}\) and \(r_{2}\). The parts of the characters that are present in this region must be identified as ascenders or descenders. Accordingly, the overlapping lines have to be segmented. Each line from the region containing the overlapping lines is segmented out one by one.  
Figure 3: Segmentation of overlapping lines from each vertical stripe into individual lines.  
For this, the beginning and end of each character in the region \(R_{ov}\) is found using the horizontal projection method. The beginning of a character is the first non-zero horizontal projection (HP) value that exists between \(r_{1}\) and \(r_{2}\). Similarly, the last non-zero HP value is the end of the character in the vertical direction. These positions can be named \(ch_{b_{\text{log}}}\) and \(ch_{a_{\text{cmd}}}\). This region is specified as the character region in the flowchart shown in Figure 3. In order to identify the presence of ascenders and descenders in this region, the row number of the largest two HP values between \(ch_{b_{\text{log}}}\) and \(ch_{a_{\text{cmd}}}\) is found. Let the row containing the highest HP value be \(rh_{p_{1}}\) and the second highest HP value be \(rh_{p_{2}}\). Now, the text line region containing the overlapping lines is divided into three parts, the upper region (\(U_{ov}\)), lower region (\(L_{ov}\)) and character region. The region above the character region is termed the upper region, \(U_{ov}\), and that below the character region is termed the lower region, denoted as \(L_{ov}\). The portion of the characters located in the region of overlapping lines is associated with the appropriate line as per the following rule.  
If (\(rh_{p_{1}}<rh_{p_{2}}\)),  
Join rows \(ch_{b_{\text{log}}}\) to \(rh_{p_{1}}-1\) to the bottom of \(U_{ov}\);  
Join rows \(rh_{p_{2}}+1\) to \(ch_{a_{\text{cmd}}}\) to the top of \(L_{ov}\).  
Otherwise,  
Join rows \(ch_{b_{\text{log}}}\) to \(rh_{p_{2}}-1\) to the bottom of \(U_{ov}\);  
Join rows \(rh_{p_{1}}+1\) to \(ch_{a_{\text{cmd}}}\) to the top of \(L_{ov}\).  
Thus, the upper region and lower region are updated. The rows between \(rh_{p_{1}}\) and \(rh_{p_{2}}\) are divided columnwise to separate the portion of the characters present in this region. This portion contains the ascenders and descenders that are responsible for the overlapping. The columnwise segmentation is performed using the vertical projection (VP) method. For each such segmented character, if the HP value in the first row is greater than that in the last row, the character is joined to the lower region, considering it as an ascender. Otherwise, it is considered as a descender and joined to the upper region.  
After segmenting the overlapped lines, it is checked whether they are short lines. The technique developed to detect the short lines is described in the next subsection.