This filter should be used if the content is arranged in several columns. A typical example is the layout of daily newspapers.
Note: The filter is not suitable for tables!
The GUI documentation for //Handle multi-column layouts// describes the current profile sidebar of i-net PDFC. The option belongs to the Enhancements group. It is intended for flowing text in multiple columns and not for table layouts.
The current implementation has no separate profile property for the number of columns. The filter is enabled by adding the identifier MULTICOLUMN to the comma-separated FILTERS list. The default value of FILTERS does not contain this identifier, so the filter is disabled by default.
| Raw key | Value | Meaning and default |
|---|---|---|
FILTERS | contains MULTICOLUMN | Enables MultiColumn processing. The list can contain additional filter identifiers. |
MULTICOLUMN | no separate profile property | The identifier is the filter name and is managed as an entry in FILTERS. |
The Handle multi-column layouts checkbox maps the UI key pdfc.filter.multicolumn to the MULTICOLUMN entry in FILTERS. Enabling adds the identifier; disabling removes it. There is no additional raw profile property for this choice.
MultiColumnFilter analyzes the extracted text elements of a page and detects a column structure from their geometry. When more than one column is detected, i-net PDFC orders the content column by column for comparison instead of processing it only line by line across the full page. Other document elements are assigned to the nearest detected column. If no multi-column structure is detected or the layout contains at most one column, the original element list is retained.
Column detection is a layout heuristic. It uses geometric and text-based criteria and is designed for at most three columns in a row. The detected structure is page-dependent; the option changes comparison order, not the PDF content.
The Multi-column text was detected. recommendation is generated by profile analysis when multiple valid columns with sufficient text are detected. The check uses leading pages within the profile-analysis limit and applies stricter text-density and column-height requirements; as a guide, each column must contain at least four fully occupied text-line equivalents. The recommendation is document-dependent guidance, not unconditional activation for every document or page.
Handle multi-column layouts optimizes the reading order of multi-column flowing text. It is not a table comparison and does not replace table or row matching. Tables should be processed with the dedicated BaselineTable option, because table structures can otherwise be interpreted as reading columns.
A possible XML profile fragment for enabling the filter is:
<entry key="FILTERS">MULTICOLUMN</entry>