Title: | Text Extraction, Rendering and Converting of PDF Documents |
---|---|
Description: | Utilities based on 'libpoppler' for extracting text, fonts, attachments and metadata from a PDF file. Also supports high quality rendering of PDF documents into PNG, JPEG, TIFF format, or into raw bitmap vectors for further processing in R. |
Authors: | Jeroen Ooms [aut, cre] |
Maintainer: | Jeroen Ooms <[email protected]> |
License: | MIT + file LICENSE |
Version: | 3.4.0 |
Built: | 2024-08-29 23:16:55 UTC |
Source: | https://github.com/ropensci/pdftools |
Perform OCR text extraction. This requires you have the tesseract
package.
pdf_ocr_text( pdf, pages = NULL, opw = "", upw = "", dpi = 600, language = "eng", options = NULL ) pdf_ocr_data( pdf, pages = NULL, opw = "", upw = "", dpi = 600, language = "eng", options = NULL )
pdf_ocr_text( pdf, pages = NULL, opw = "", upw = "", dpi = 600, language = "eng", options = NULL ) pdf_ocr_data( pdf, pages = NULL, opw = "", upw = "", dpi = 600, language = "eng", options = NULL )
pdf |
file path or raw vector with pdf data |
pages |
which pages of the pdf file to extract |
opw |
string with owner password to open pdf |
upw |
string with user password to open pdf |
dpi |
resolution to render image that is passed to pdf_convert. |
language |
passed to tesseract to specify the languge of the engine. |
options |
passed to tesseract to specify OCR parameters |
Other pdftools:
pdftools
,
qpdf
,
rendering
Utilities based on libpoppler for extracting text, fonts, attachments and metadata from a pdf file.
pdf_info(pdf, opw = "", upw = "") pdf_text(pdf, opw = "", upw = "") pdf_data(pdf, font_info = FALSE, opw = "", upw = "") pdf_fonts(pdf, opw = "", upw = "") pdf_attachments(pdf, opw = "", upw = "") pdf_toc(pdf, opw = "", upw = "") pdf_pagesize(pdf, opw = "", upw = "")
pdf_info(pdf, opw = "", upw = "") pdf_text(pdf, opw = "", upw = "") pdf_data(pdf, font_info = FALSE, opw = "", upw = "") pdf_fonts(pdf, opw = "", upw = "") pdf_attachments(pdf, opw = "", upw = "") pdf_toc(pdf, opw = "", upw = "") pdf_pagesize(pdf, opw = "", upw = "")
pdf |
file path or raw vector with pdf data |
opw |
string with owner password to open pdf |
upw |
string with user password to open pdf |
font_info |
if TRUE, extract font-data for each box. Be careful, this requires a very recent version of poppler and will error otherwise. |
The pdf_text
function renders all textboxes on a text canvas
and returns a character vector of equal length to the number of pages in the
PDF file. On the other hand, pdf_data
is more low level and
returns one data frame per page, containing one row for each textbox in the PDF.
Note that pdf_data
requires a recent version of libpoppler
which might not be available on all Linux systems.
When using pdf_data
in R packages, condition use on
poppler_config()$has_pdf_data
which shows if this function can be
used on the current system. For Ubuntu 16.04 (Xenial) and 18.04 (Bionic)
you can use the PPA
with backports of Poppler 0.74.0.
Poppler is pretty verbose when encountering minor errors in PDF files,
in especially pdf_text
. These messages are usually safe
to ignore, use suppressMessages
to hide them altogether.
Other pdftools:
pdf_ocr_text()
,
qpdf
,
rendering
# Just a random pdf file pdf_file <- file.path(R.home("doc"), "NEWS.pdf") info <- pdf_info(pdf_file) text <- pdf_text(pdf_file) fonts <- pdf_fonts(pdf_file) files <- pdf_attachments(pdf_file)
# Just a random pdf file pdf_file <- file.path(R.home("doc"), "NEWS.pdf") info <- pdf_info(pdf_file) text <- pdf_text(pdf_file) fonts <- pdf_fonts(pdf_file) files <- pdf_attachments(pdf_file)
High quality conversion of pdf page(s) to png, jpeg or tiff format, or render into a raw bitmap array for further processing in R.
pdf_render_page( pdf, page = 1, dpi = 72, numeric = FALSE, antialias = TRUE, opw = "", upw = "" ) pdf_convert( pdf, format = "png", pages = NULL, filenames = NULL, dpi = 72, antialias = TRUE, opw = "", upw = "", verbose = TRUE ) poppler_config()
pdf_render_page( pdf, page = 1, dpi = 72, numeric = FALSE, antialias = TRUE, opw = "", upw = "" ) pdf_convert( pdf, format = "png", pages = NULL, filenames = NULL, dpi = 72, antialias = TRUE, opw = "", upw = "", verbose = TRUE ) poppler_config()
pdf |
file path or raw vector with pdf data |
page |
which page to render |
dpi |
resolution (dots per inch) to render |
numeric |
convert raw output to (0-1) real values |
antialias |
enable antialiasing. Must be |
opw |
owner password |
upw |
user password |
format |
string with output format such as |
pages |
vector with one-based page numbers to render. |
filenames |
vector of equal length to |
verbose |
print some progress info to stdout |
Other pdftools:
pdf_ocr_text()
,
pdftools
,
qpdf
# Rendering should be supported on all platforms now # convert few pages to png file.copy(file.path(Sys.getenv("R_DOC_DIR"), "NEWS.pdf"), "news.pdf") pdf_convert("news.pdf", pages = 1:3) # render into raw bitmap bitmap <- pdf_render_page("news.pdf") # save to bitmap formats png::writePNG(bitmap, "page.png") webp::write_webp(bitmap, "page.webp") # Higher quality bitmap <- pdf_render_page("news.pdf", page = 1, dpi = 300) png::writePNG(bitmap, "page.png") # slightly more efficient bitmap_raw <- pdf_render_page("news.pdf", numeric = FALSE) webp::write_webp(bitmap_raw, "page.webp") # Cleanup unlink(c('news.pdf', 'news_1.png', 'news_2.png', 'news_3.png', 'page.jpeg', 'page.png', 'page.webp'))
# Rendering should be supported on all platforms now # convert few pages to png file.copy(file.path(Sys.getenv("R_DOC_DIR"), "NEWS.pdf"), "news.pdf") pdf_convert("news.pdf", pages = 1:3) # render into raw bitmap bitmap <- pdf_render_page("news.pdf") # save to bitmap formats png::writePNG(bitmap, "page.png") webp::write_webp(bitmap, "page.webp") # Higher quality bitmap <- pdf_render_page("news.pdf", page = 1, dpi = 300) png::writePNG(bitmap, "page.png") # slightly more efficient bitmap_raw <- pdf_render_page("news.pdf", numeric = FALSE) webp::write_webp(bitmap_raw, "page.webp") # Cleanup unlink(c('news.pdf', 'news_1.png', 'news_2.png', 'news_3.png', 'page.jpeg', 'page.png', 'page.webp'))