manipulate

package
v1.9.0 Latest Latest
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 Go to latest Published: May 12, 2026 License: MIT Imports: 12 Imported by: 0

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Index

Constants

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Variables

This section is empty.

Functions

func AddAnnotation added in v1.5.0 

func AddAnnotation(pdfBytes []byte, pageNumber int, cfg AnnotationConfig, password []byte, verbose bool) ([]byte, error)

AddAnnotation adds a single annotation to the given page (1-based) of pdfBytes.

func ConvertToPDFA added in v1.5.0 

func ConvertToPDFA(pdfBytes []byte, password []byte, conformance string) ([]byte, error)

ConvertToPDFA converts a PDF to PDF/A format.

conformance selects the conformance level:

  • "1b" → PDF/A-1b (default when empty)
  • "2b" → PDF/A-2b
  • "3b" → PDF/A-3b

PDF/A cannot be encrypted, so if the input PDF is encrypted it is first decrypted using password. The output is always unencrypted.

func CropPage added in v1.5.0 

func CropPage(pdfBytes []byte, pageNumber int, rect [4]float64, password []byte, verbose bool) ([]byte, error)

CropPage sets /CropBox on the specified page (1-based). rect is [llx lly urx ury] in PDF user units (points).

func DecryptPDF added in v1.5.0 

func DecryptPDF(pdfBytes []byte, password []byte, verbose bool) ([]byte, error)

DecryptPDF produces a fully decrypted, plaintext PDF from an encrypted one. It verifies the password, decrypts every stream and string in the document, removes the /Encrypt dict and all encryption metadata, and returns clean bytes that can be opened by any PDF tool without a password.

Returns an error if the password is wrong or the PDF cannot be parsed. If the PDF is already unencrypted the original bytes are returned unchanged.

func DeletePage added in v1.5.0 

func DeletePage(pdfBytes []byte, pageNumber int, password []byte, verbose bool) ([]byte, error)

DeletePage removes a single page from pdfBytes (1-based page number).

func DeletePages added in v1.5.0 

func DeletePages(pdfBytes []byte, pageNumbers []int, password []byte, verbose bool) ([]byte, error)

DeletePages removes multiple pages from pdfBytes (1-based page numbers).

func DuplicatePage added in v1.5.0 

func DuplicatePage(pdfBytes []byte, pageNumber, copies int, password []byte, verbose bool) ([]byte, error)

DuplicatePage inserts copies copies of pageNumber immediately after it (1-based).

func EncryptPDF added in v1.5.0 

func EncryptPDF(pdfBytes []byte, userPassword, ownerPassword []byte, verbose bool) ([]byte, error)

EncryptPDF applies AES-128 (V=4, R=4) encryption to an existing unencrypted PDF. It is the write-side counterpart to encrypt.DecryptPDF.

userPassword is required to open the document; ownerPassword grants full control. Either may be nil or empty (no password for that role).

Returns an error if the input PDF is already encrypted or cannot be parsed.

func ExtractPages 

func ExtractPages(pdfBytes []byte, pageNumbers []int, password []byte, verbose bool) ([]byte, error)

ExtractPages extracts specific pages from a PDF and returns a new PDF containing only those pages, with all their dependencies (fonts, images, content streams, etc.) fully copied and object references remapped. pageNumbers is 1-based.

func InsertBlankPage added in v1.5.0 

func InsertBlankPage(pdfBytes []byte, position int, width, height float64, password []byte, verbose bool) ([]byte, error)

InsertBlankPage inserts a blank page at position (1-based; 0 = append at end). width and height are in PDF user units (points).

func Linearize added in v1.5.0 

func Linearize(pdfBytes []byte, password []byte) ([]byte, error)

Linearize rewrites a PDF for fast web delivery ("Fast Web View"). It:

  • flattens all incremental updates into a single revision
  • reorders objects so the catalog and first page appear early in the file
  • adds a /Linearized parameter dictionary as the first object

The /H (hint stream) field is omitted; PDF readers fall back to sequential reading gracefully when hints are absent. For encrypted PDFs supply the password; the output will be unencrypted (linearization requires plaintext).

func MergePDFs 

func MergePDFs(pdfBytesList [][]byte, passwords [][]byte, verbose bool) ([]byte, error)

MergePDFs merges multiple PDFs into a single PDF Returns a new PDF with all pages from all input PDFs

func Redact added in v1.5.0 

func Redact(pdfBytes []byte, boxes []RedactBox, password []byte) ([]byte, error)

Redact permanently removes content within the specified regions and replaces each area with an opaque black rectangle. It:

  • rewrites page content streams to suppress text/path operators inside boxes
  • zeros out image XObject streams whose placement overlaps a box
  • zeros out annotation objects (text, links, highlights, etc.) whose /Rect overlaps a box

XMP metadata and /Info dictionary entries are not cleared by this call; call RedactMetadata separately for document-level metadata.

Note: PDF incremental updates may contain prior revisions. Supply a clean (already-repaired/flattened) source PDF for full forensic redaction; or call Repair first.

func RedactMetadata added in v1.5.0 

func RedactMetadata(pdfBytes []byte, password []byte, verbose bool) ([]byte, error)

RedactMetadata removes document metadata from pdfBytes:

  • Clears the /Info object (replaces its content with an empty dict).
  • Removes the /Metadata stream from the document catalog.
  • Drops the InfoRef from the rebuilt trailer.

func ReorderPages added in v1.5.0 

func ReorderPages(pdfBytes []byte, order []int, password []byte, verbose bool) ([]byte, error)

ReorderPages reorders pages according to order, which is a 1-based slice of page numbers representing the desired output order. order must be a permutation of [1..pageCount]: same length as the current page count, each page number appearing exactly once.

func Repair added in v1.5.0 

func Repair(pdfBytes []byte, password []byte) ([]byte, error)

Repair rebuilds a PDF into a clean single-revision form:

  • flattens all incremental updates into one revision
  • removes orphaned cross-reference entries
  • rebuilds the xref table from scratch
  • preserves all content, resources, and metadata

It does not validate or fix content-stream operators. For encrypted PDFs supply the password; the output will be unencrypted.

func ReplaceImage added in v1.5.0 

func ReplaceImage(pdfBytes []byte, imageRef string, newImageData []byte, format string, password []byte, verbose bool) ([]byte, error)

ReplaceImage replaces an image XObject in a PDF.

imageRef identifies the image either by its XObject resource name (e.g. "Im1", "Img0") or by the raw object number as a decimal string (e.g. "7").

format must be "jpeg", "png", or "raw".

  • "jpeg": newImageData must be a JPEG file; the stream is stored with /Filter/DCTDecode.
  • "png": newImageData must be a PNG file; the image is decoded and stored as raw deflate-compressed RGB pixels with /Filter/FlateDecode.
  • "raw": the stream bytes are replaced as-is; the existing filter is preserved.

func RotateAllPages added in v1.5.0 

func RotateAllPages(pdfBytes []byte, angle int, password []byte, verbose bool) ([]byte, error)

RotateAllPages rotates every page in pdfBytes by angle degrees (90, 180, or 270).

func RotatePage added in v1.5.0 

func RotatePage(pdfBytes []byte, pageNumber, angle int, password []byte, verbose bool) ([]byte, error)

RotatePage rotates a single page in pdfBytes by angle degrees (90, 180, or 270).

func SetBookmarks added in v1.5.0 

func SetBookmarks(pdfBytes []byte, bookmarks []BookmarkEntry, password []byte, verbose bool) ([]byte, error)

SetBookmarks replaces all bookmarks in pdfBytes with the given tree. If bookmarks is empty or nil, all existing bookmarks are removed.

func SetMetadata added in v1.5.0 

func SetMetadata(pdfBytes []byte, meta MetadataUpdate, password []byte, verbose bool) ([]byte, error)

SetMetadata updates the /Info dictionary of a PDF. For each field in meta that is non-empty the corresponding /Info entry is created or replaced. Fields that are empty strings are left unchanged.

func SetPageSize added in v1.5.0 

func SetPageSize(pdfBytes []byte, pageNumber int, width, height float64, password []byte, verbose bool) ([]byte, error)

SetPageSize sets /MediaBox on the specified page (1-based). The new MediaBox is [0 0 width height].

func SplitPDF 

func SplitPDF(pdfBytes []byte, pageRanges []PageRange, password []byte, verbose bool) ([][]byte, error)

SplitPDF splits a PDF into multiple PDFs based on page ranges pageRanges is a slice of page number ranges, e.g., []PageRange{{1, 3}, {4, 5}} Returns a slice of PDF bytes, one for each range

func SplitPDFByPageCount 

func SplitPDFByPageCount(pdfBytes []byte, pagesPerPDF int, password []byte, verbose bool) ([][]byte, error)

SplitPDFByPageCount splits a PDF into multiple PDFs with a fixed number of pages each Returns a slice of PDF bytes

func StampAllPages added in v1.5.0 

func StampAllPages(pdfBytes []byte, stamp TextStamp, password []byte, verbose bool) ([]byte, error)

StampAllPages adds the same text overlay to every page of pdfBytes.

func StampPageNumbers added in v1.5.0 

func StampPageNumbers(pdfBytes []byte, opts PageNumberOptions, password []byte, verbose bool) ([]byte, error)

StampPageNumbers adds automatic page numbers to all pages of pdfBytes.

func StampText added in v1.5.0 

func StampText(pdfBytes []byte, pageNumber int, stamp TextStamp, password []byte, verbose bool) ([]byte, error)

StampText adds a text overlay to one page of pdfBytes (1-based page number).

Types

type AnnotationConfig added in v1.5.0 

type AnnotationConfig struct {
	Type     AnnotationType
	Rect     [4]float64 // [llx lly urx ury] in page coordinates
	Contents string     // visible text (Text, FreeText) or tooltip (Link)

	// Link-specific: set URI for external links, or DestPage (1-based) for internal.
	URI      string
	DestPage int

	// Colour (RGB 0–1); zero value = default for type.
	Color [3]float64

	// Opacity 0–1; 0 means use default (fully opaque).
	Opacity float64
}

AnnotationConfig describes an annotation to be added to a page.

type AnnotationType added in v1.5.0 

type AnnotationType string

AnnotationType identifies the PDF annotation subtype. 

const (
	AnnotText      AnnotationType = "Text"
	AnnotLink      AnnotationType = "Link"
	AnnotFreeText  AnnotationType = "FreeText"
	AnnotHighlight AnnotationType = "Highlight"
	AnnotUnderline AnnotationType = "Underline"
	AnnotStrikeOut AnnotationType = "StrikeOut"
)

type BookmarkEntry added in v1.5.0 

type BookmarkEntry struct {
	Title    string          // displayed text
	Page     int             // 1-based destination page (0 = no destination)
	Children []BookmarkEntry // nested entries
}

BookmarkEntry describes one entry in the PDF outline (bookmark) tree.

type MetadataUpdate added in v1.5.0 

type MetadataUpdate struct {
	Title    string
	Author   string
	Subject  string
	Keywords string
	Creator  string
	Producer string
}

MetadataUpdate holds the fields to update in the /Info dictionary. An empty string means "leave unchanged".

type PDFManipulator 

type PDFManipulator struct {
	// contains filtered or unexported fields
}

PDFManipulator provides functions to modify existing PDFs

func NewPDFManipulator 

func NewPDFManipulator(pdfBytes []byte, password []byte, verbose bool) (*PDFManipulator, error)

NewPDFManipulator creates a new PDF manipulator from existing PDF bytes

func (*PDFManipulator) ApplyRedactions added in v1.5.0 

func (m *PDFManipulator) ApplyRedactions(boxes []RedactBox) error

ApplyRedactions modifies the manipulator in-place, applying redaction to the specified page regions. Call Rebuild() afterwards to emit the modified PDF.

func (*PDFManipulator) DeletePage 

func (m *PDFManipulator) DeletePage(pageNumber int) error

DeletePage deletes a specific page from the PDF pageNumber is 1-based (first page is 1)

func (*PDFManipulator) DeletePages 

func (m *PDFManipulator) DeletePages(pageNumbers []int) error

DeletePages deletes multiple pages from the PDF pageNumbers is 1-based and should be sorted in descending order to avoid index shifts

func (*PDFManipulator) InsertPage 

func (m *PDFManipulator) InsertPage(pageNumber int, pageObjNum int, pageContent []byte) error

InsertPage inserts a page at a specific position pageNumber is 1-based (first page is 1, 0 means insert at end) The page to insert must be from another PDF (use ExtractPages first)

func (*PDFManipulator) Rebuild 

func (m *PDFManipulator) Rebuild() ([]byte, error)

Rebuild rebuilds the PDF with modified objects and returns the new PDF bytes

func (*PDFManipulator) RotateAllPages 

func (m *PDFManipulator) RotateAllPages(angle int) error

RotateAllPages rotates all pages by the given angle

func (*PDFManipulator) RotatePage 

func (m *PDFManipulator) RotatePage(pageNumber int, angle int) error

RotatePage rotates a specific page by the given angle (90, 180, or 270 degrees) pageNumber is 1-based (first page is 1)

func (*PDFManipulator) StampAllPages added in v1.5.0 

func (m *PDFManipulator) StampAllPages(stamp TextStamp) error

StampAllPages adds the same text overlay to every page.

func (*PDFManipulator) StampPageNumbers added in v1.5.0 

func (m *PDFManipulator) StampPageNumbers(opts PageNumberOptions) error

StampPageNumbers adds page numbers to all pages.

func (*PDFManipulator) StampText added in v1.5.0 

func (m *PDFManipulator) StampText(pageNumber int, stamp TextStamp) error

StampText adds a text overlay to the specified page (1-based).

type PageNumberOptions added in v1.5.0 

type PageNumberOptions struct {
	FontName string             // standard font; default "Helvetica"
	FontSize float64            // default 10
	Format   string             // printf-style; one %d = page, two %d = (page, total); default "%d"
	Position PageNumberPosition // default BottomCenter
	MarginX  float64            // extra inset from page edge, default 36 pt
	MarginY  float64            // extra inset from page edge, default 36 pt
	R, G, B  float64            // fill colour, 0–1 each; default black
}

PageNumberOptions configures automatic page-number stamping.

type PageNumberPosition added in v1.5.0 

type PageNumberPosition int

PageNumberPosition controls where page numbers are placed. 

const (
	BottomCenter PageNumberPosition = iota
	BottomRight
	BottomLeft
	TopCenter
	TopRight
	TopLeft
)

type PageRange 

type PageRange struct {
	Start int // First page number (1-based)
	End   int // Last page number (1-based, inclusive)
}

PageRange represents a range of pages (1-based, inclusive)

type Permissions added in v1.5.0 

type Permissions struct {
	Print            bool
	Modify           bool
	Copy             bool
	AddAnnotations   bool
	FillForms        bool
	ExtractForAccess bool
	Assemble         bool
	PrintHighQuality bool
}

Permissions describes the permission flags encoded in the /P field of an encrypted PDF's /Encrypt dictionary.

func GetPermissions added in v1.5.0 

func GetPermissions(pdfBytes []byte, password []byte) (*Permissions, error)

GetPermissions returns the permission flags for pdfBytes. For unencrypted PDFs all flags are returned as true. For encrypted PDFs the /P integer from the /Encrypt dictionary is decoded per the PDF specification.

type RedactBox added in v1.5.0 

type RedactBox struct {
	Page int        // 1-indexed page number
	Rect [4]float64 // [llx lly urx ury] in PDF user space (points from bottom-left)
}

RedactBox specifies a rectangular region to redact on a particular page.

type TextStamp added in v1.5.0 

type TextStamp struct {
	Text     string  // text to render
	FontName string  // standard Type1 font name; default "Helvetica"
	FontSize float64 // in points; default 12
	X, Y     float64 // position in points from bottom-left of the page
	R, G, B  float64 // fill colour, 0–1 each; default black
	Angle    float64 // rotation in degrees, counter-clockwise; default 0
	Opacity  float64 // 0 = transparent, 1 = opaque; default 1
}

TextStamp describes a text overlay to paint onto a page.

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