Finding the right "Context aware object detection" property

Checks based on "Context aware object detection" properties can be configured in a various ways.

  1. There around 20 relatively simple variants that address specific use cases – if they match a certain requirement, it's best to start from such an easy to use variant.
  2. There is master version of "Context aware object detection", which is called like the Group itself: "Context aware object detection (Sifter)". It offers a highly flexible but also possibly challenging approach to setting up a context aware object detection check.
  3. Last but not least there is the "Shapes" property, which can only be used in the context of "Context aware object detection" checks: such a Shape property make it possible to flexibly define areas – for example the area defined by the outer border of all cut lines on a page – against which to detect certain objects.

The remainder of this article gives an overview of the available "Context aware object detection" properties, followed by one example that demonstrates how to set up a check based on the "Object reaches into edge area of a shape" property.

Where to find the "Context aware object detection" properties

When creating a new check, under "Group" look for the "Context aware object detection" entry. Upon selecting that entry, under "Property" all the properties belonging to the "context aware object detection" group will be listed.

List of special purpose context aware object detection options

  • Proximity:
    • Object reaches into edge area of a shape:
      Determines whether the extent of a graphics object ends inside the edge area of a shape. 
    • Object crosses shape:
      Determines whether the edge of a graphics object visibly crosses the edge of the area defined by a shape. Clipping as well as obliteration by other objects are taken into account, whereas z order is not taken into account.
  • Above versus below:
    • Object on top of other object(s):
      Determines whether a graphics object visibly overlaps some other graphics object (where that other graphics object has a lower z order value). Clipping as well as obliteration by other objects are taken into account.
    • Object not on top of any other object:
      Finds graphics objects that do not visibly overlaps any other graphics object (where that other graphics object has a lower z order value) on the page. Clipping as well as obliteration by other objects are taken into account.
    • Object covers other object:
      Determines whether a graphics object visibly covers some other graphics object (where that other graphics object has a lower z order value). Clipping as well as obliteration by other objects are taken into account. Depending on applicable overprint and transparency properties, the object below may be visible or not.
    • Object below other object: Object below other object:
      Determines whether a graphics object is visibly overlapped by some other graphics object (where that other graphics object has a higher z order value). Clipping as well as obliteration by other objects are taken into account.
    • Object not below any other object:
      Finds graphics objects that are not visibly overlapped by any other graphics object (where that other graphics object has a higher z order value). Clipping as well as obliteration by other objects are taken into account.
    • Object covered by other object:
      Determines whether a graphics object is visibly covered by some other graphics object (where that other graphics object has a higher z order value). Clipping as well as obliteration by other objects are taken into account. Depending on applicable overprint and transparency properties, the covered object may be visible or not.
  • Inside versus outside:
    • Object inside other object:
      Determines whether the extent of a graphics object visibly lies completely inside the area occupied by some other graphics object. Clipping as well as obliteration by other objects are taken into account, whereas z order is not taken into account.
    • Object inside shape:
      Determines whether the extent of a graphics object visibly lies completely inside the area defined by a shape. Clipping as well as obliteration by other objects are taken into account, whereas z order is not taken into account.
    • Object outside other object:
      Determines whether the extent of a graphics object visibly lies completely outside the area occupied by some other graphics object. Clipping as well as obliteration by other objects are taken into account, whereas z order is not taken into account.
    • Object outside shape:
      Determines whether the extent of a graphics object visibly lies completely outside the area defined by a shape. Clipping as well as obliteration by other objects are taken into account, whereas z order is not taken into account.
    • Object crosses other object:
      Determines whether the edge of a graphics object visibly crosses the edge of some other graphics object. Clipping as well as obliteration by other objects are taken into account, whereas z order is not taken into account.
  • Visible, partially visible or invisible
    • Object is invisible:
      Determines the visibility of a graphics object. An object may be invisible due to clipping – through explicit clipping paths, or due to CropBox and MediaBox – or obliteration by other objects that are opaque. 
    • Object is visible:
      Determines the visibility of a graphics object. An object may be invisible due to clipping – through explicit clipping paths, or due to CropBox and MediaBox – or obliteration by other objects that are opaque. 
    • Object is partially obliterated:
      Determines whether a part of a graphics object is obliterated by other opaque graphics objects. Completely obliterated graphics objects are not found by this property.
    • Object is completely obliterated:
      Determines the visibility, or lack thereof, of a graphics object caused by obliteration. An object may be invisible due to clipping – through explicit clipping paths, or due to CropBox and MediaBox – or obliteration by other objects that are opaque. 
    • Object is partially clipped:
      Determines whether a part of a graphics object is clipped (through explicit clipping paths, or due to CropBox and MediaBox). Completely clipped graphics objects are not found by this property.
    • Object is completely clipped:
      Determines the visibility, or lack thereof, of a graphics object caused by clipping. An object may be invisible due to clipping – through explicit clipping paths, or due to CropBox and MediaBox – or obliteration by other objects that are opaque. 

Example: Configuring the «Object reaches into edge area of a shape» property

Create a new check using the fly out menu in the upper right of the "Checks" window (open from "Tools" menu via "Checks" menu entry). In the "New Check" dialog, start configuring the context aware object detection check "Object too close to cutline":

  1. Enter a suitable name for the check
  2. Select the "Context aware object detection" group in the "Group" list.
  3. Next select the "Object reaches into edge area of a shape" property in "Property" list, then click the "Add" button in that list entry.
  4. A list of configuration options will show up below the "Group" and "Property" lists.
  1. Select a check that finds the objects you are interested in. In this example, we want to check for text objects that may be too close to a cutline.
  2. If there is no "Is text" check yet, simply create a new one using the "+" button to the right of the popup menu with the list of already existing checks.
  3. Choose a suitable check in the second popup menu that will find lines using a spot color "Cutline". If there is not such a check yet, simply create a new one using the "+" button to the right of the popup menu with the list of already existing checks.
  4. Next, enter suitable values to use when checking the distance of above configured text objects against any line colored with the spot color "Cutline". Due to the fact that for any object only the area that it actually covers is taken into account, there is not a lot of area inside the line (i.e. the inside area essentially just has an extent equal to the line width) so more important is the outside edge of the line: fill in a number that matches production requirements.
  5. Set the measurement unit for the "Inner edge area" and the "Outer edge area" to whatever may be most convenient. Supported measurement units are millimeters (mm), point (pt) and inch (in).

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