16 Optional Content Groups

cpdf -ocg-list in.pdf

cpdf -ocg-rename -ocg-rename-from <a> -ocg-rename-to <b> in.pdf -o out.pdf

cpdf -ocg-order-all in.pdf -o out.pdf

cpdf -ocg-coalesce-on-name in.pdf -o out.pdf

In a PDF file, optional content groups are used to group graphical elements together, so they may appear or not, depending on the preference of the user. They are similar in some ways to layers in graphics illustration programs.

List the optional content groups in the PDF, one per line, to standard output. UTF8.

Coalesce optional content groups. For example, if we merge or stamp two files both with an OCG called ”Layer 1”, we will have two different optional content groups. Running -ocg-coalesce-on-name will merge the two into a single optional content group.

.NET Interface

CHAPTER 16. Optional Content Groups

Cpdf.startGetOCGList(Cpdf.Pdf)

Begins retrieving optional content group names. The serial number 0..n - 1 is
returned.

Cpdf.OCGListEntry(Int32)

Retrieves an OCG name, given its serial number 0..n - 1.

Cpdf.endGetOCGList

Ends retrieval of optional content group names.

Cpdf.OCGRename(Cpdf.Pdf, String, String)

Renames an optional content group.

Cpdf.OCGOrderAll(Cpdf.Pdf)

Ensures that every optional content group appears in the OCG order list.

Cpdf.OCGCoalesce(Cpdf.Pdf)

Coalesces optional content groups. For example, if we merge or stamp two files
both with an OCG called "Layer 1", we will have two different optional content
groups. This function will merge the two into a single optional content group.

Chapter 16Optional Content Groups

.NET Interface

Chapter 16
Optional Content Groups