How to Define Annotations

How to Define PDF Annotations in PDFix Desktop

Define the Annotations to which the specific action is applied. Combo box Annotations gives you multiple options how to do that.

• Check Annotations
• Select a Predefined Annotations Sets
• Define the annotation using Regular Expression Format
• Define the annotation by Template

Check Annotation Types

In the combo box you can simply check annotations types you want to process.

Predefined Annotation Sets

For each action, there are predefined subsets of annotations defined by regex or template. For example, Ignore Hidden and Invisible processes each annotation that is neither hidden nor invisible.

Define Annotations by Regex

Annotation types can be easily defined using a regular expression. You can enter the regular expression into the Annotations combo box, or select from predefined or saved regex formulas.

To add a favorite regex, use Add Regex, accessible by right-clicking in the combo box or clicking the menu icon

For example:

Test the regex on https://regex101.com/

Define Annotations by Template

Define by template option allows you to define more complex query for annotations. Select the option Add Template from the combo box menu.

In the Edit template dialog you can define conditions which annotations should be processed in the annot_update node. The system of defining conditions is the same like in the template panel.

Below you can find examples of commonly used templates. In the Edit template dialog choose the Plain Template option and replace the code with examples bellow.

Example 1: All annotations except hidden and invisible

{
    "template": {
        "annot_update": [
            {
                "query": {
                    "$and": [
                        {
                            "$0_annot_type": {
                                "$regex": ".*"
                            }
                        },
                        {
                            "$not": [
                                {
                                    "$0_annot_flag": {
                                        "$regex": "invisible"
                                    }
                                }
                            ]
                        },
                        {
                            "$not": [
                                {
                                    "$0_annot_flag": {
                                        "$regex": "hidden"
                                    }
                                }
                            ]
                        }
                    ],
                    "param": [
                        "pdf_annot"
                    ]
                },
                "statement": "$if"
            }
        ]
    }
}

Example 2: Link annotations with empty Contents key

{
    "template": {
        "annot_update": [
            {
                "query": {
                    "$and": [
                        {
                            "$0_annot_type": {
                                "$regex": "^Link$"
                            }
                        },
                        {
                            "$0_contents": ""
                        }
                    ],
                    "param": [
                        "pdf_annot"
                    ]
                },
                "statement": "$if"
            }
        ]
    }
}

Example 3: All annotations with specific box

This template matches annotations on page 1 that are small in size (width and height <= 14 points). It’s useful for identifying decorative or icon-like annotations (e.g. small link icons, UI hints) that might not require detailed alternative text for accessibility.

{
  "template": {
    "annot_update": [
      {
        "query": {
          "$and": [
            {
              "$0_width": {
                "$lte": "14"   // width less than or equal to 14 pt
              }
            },
            {
              "$0_height": {
                "$lte": "14"   // height less than or equal to 14 pt
              }
            },
            {
              "$page_num": "1" // only match annotations on page 1
            }
          ],
          "param": [
            "pdf_annot"
          ]
        },
        "statement": "$if"
      }
    ]
  }
}