The APM engine uses a configurable horizontal and vertical margins, dimensions of the empty space to ignore, search tolerance dimensions and overlap percentage to finely tune the free space recognition of an editorial hole on a page.

Depending on the values of the aforementioned configurable parameters, matching of a given editorial hole with the objects in the APM object libraries may have success of fail.

Horizontal tolerance

The horizontal tolerance is the minimum space that has to exist on the left and the right side of an APM object in order to elect the object. The space on the left is ignored for the APM objects that start on the left page margin. The space on the right is ignored for the APM objects that end on the right page margin.

The default horizontal tolerance is half of the page column gutter. This also assumes that the smallest allowed horizontal distance between editorial content and ads is the value of the default horizontal tolerance. You can change the horizontal tolerance on the title level. If unsure, set the value 1 pt or 2 pt less than the page column gutter.

See Configure the editorial hole tolerance.

Vertical tolerance

The vertical tolerance is the minimum space that has to exist on the top and the bottom side of an APM object in order to elect the object. The space on the top is ignored for the APM objects that start on the top page margin. The space on the bottom is ignored for the APM objects that end on the bottom page margin.

The default vertical tolerance is the page module height. This also assumes that the smallest allowed vertical distance between editorial content and ads is the value of the default vertical tolerance. You can change the vertical tolerance on the title level.

See Configure the editorial hole tolerance.

Empty space tolerance

The empty space tolerance is the width/height of the space to be ignored if detected by the APM free space discovery.

The default empty space value is 50pt. This means that the empty spaces of 50pt or less are not counted as the usable free space.

Search tolerance

The search tolerance is the range of acceptable differences between the shape and the editorial hole.

The default search tolerance is 50pt. This means that, if two editorial shapes in two object libraries differ between them for less of 50pt, the object in the first found library will be used.

Overlap tolerance

The overlap tolerance is the acceptable percentage of overlap between editorial shape and underlying objects.

The default overlap is 10%. This means that if a library object overlaps the ads for 10% or less, it will be elected and placed on page. This assumes that APM will change the object dimensions not to overlap with ads.

The purpose of the tolerance

The purpose of the tolerance is to:

•Handle the small variations of ads sizes without real impact on the page layout. E.g. your ads height can be 339pt, 340pt, 341pt, 342pt.

•Handle small variations of the gaps between the ads and the content.