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tclMuPDF 1.4 Tcl meets MuPDF

Tcl meets MuPDF

SYNOPSIS edit

package require Tcl 8.5

package require mupdf ?1.4?

• mupdf::open filename ?-password password?
• pdfHandle fullname
• pdfHandle authentication
• pdfHandle version
• pdfHandle npages
• pdfHandle getpage n
• pdfHandle anchor anchorName
• pdfHandle openedpages
• pdfHandle closeallpages
• pdfHandle fields
• pdfHandle field fieldname
• pdfHandle signatures
• pdfHandle haschanges
• pdfHandle canbesavedincrementally
• pdfHandle export filename
• pdfHandle portfolio list
• psdHandle portfolio extract i ?-dir pathname? ?-as filename?
• pdfHandle search needle ?-startpage pagenum? ?-max hits?
• pdfHandle search..more ?-max hits?
• pageHandle size
• pageHandle docref
• pageHandle pagenumber
• pageHandle savePNG filename ?-zoom zoom? ?-from x0 y0 x1 y1?
• pageHandle saveImage image ?-zoom zoom? ?-from x0 y0 x1 y1? ?-to x0 y0?
• pageHandle addsigfield fieldname x0 y0 x1 y1
• pageHandle search needle ?-fromtop true/false? ?-max hits?
• pageHandle images list ?-id imageID?
• pageHandle images extract ?-id imageID? ?-dir pathname? ?-as pattern? ?-transparency boolean?
• mupdf::imagenamesformat ?pattern?
• mupdf::close handle
• mupdf::quit pdfHandle
• mupdf::isobject handle
• mupdf::type handle
• mupdf::documents
• mupdf::documentnames
• mupdf::isopen filename
• mupdf::cli_passwordhelper ?helperProc?
• mupdf::tk_passwordhelper ?helperProc?
• mupdf::libinfo

DESCRIPTION edit

Package mupdf integrates the MuPDF framework in Tcl. The focus of MuPDF is on speed, small code size, and high-quality anti-aliased rendering. The main goal of this integration is to generate images of the pdf pages, in a .png format, or directly in a Tk's photo image type. Thanks to its speed mupdf can be used for building interactive pdf-viewers with high-quality and real-time zooming. mupdf is a binary package, distributed in a multi-platform bundle, i.e. it can be used on

• Windows 32/64 bit
• Linux 32/64 bit
• MacOS 64 bit

Just an example to get the flavor of how to use mupdf:

    # open a file and save 1st page as a .png file

    package require mupdf
    set pdf [mupdf::open /mydir/sample.pdf]
    set page [$pdf getpage 0]   ;# 0 is the 1st page
    $page savePNG /mydir/page0.png
    mupdf::close $pdf

MuPDF with and without Tk edit

Starting from version 1.1, you can also run mupdf from a tclsh interpreter, without loading Tk. The following command

package require mupdf-notk

can be used in a tclsh interpreter to load the package without requiring Tk support. You will be still able to save images as PNG files, but of course some subcommands related to Tk won't be available (e.g saveImage ) The command

package require mupdf

loads the full package (and requires Tk).

mupdf Commands edit

mupdf supports the following commands:

mupdf::open filename ?-password password?

This is the main command: it opens the PDF-file filename and returns a pdfHandle to be used in subsequent operations. If filename is password-protected, you may specify a password adding the option -password; if option -password is not specified, mupdf will ask for a password.] Read more about it in the section Working with Password Protected Files.

pdfHandle fullname

return the fully normalized pathname of the pdf-file.

pdfHandle authentication

return the current authentication mode for pdfHandle. It may be none (no auth required), user (opened with user's password), owner (opened with owner's password).

pdfHandle version

return the document's internal PDF-version.

pdfHandle npages

return the number of pages.

pdfHandle getpage n

return a pageHandle to be used in subsequent operations. Note that first page is page 0. Note that if the requested page is currently opened, getpage reuses the handle of the opened page.

pdfHandle anchor anchorName

return the location of anchorName as list of 3 numbers:

• a page number ( -1 if anchorName is not found )
• x displacement
• y displacement x and y are hints for displaying the page: they represent the displacement of the top-left corner of the page relative to the top-left corner of the window.

pdfHandle openedpages

return the list of all pageHandles currently opened related to pdfHandle

pdfHandle closeallpages

close all currently opened pages related to pdfHandle

pdfHandle fields

return a list of field-records. Each field-record is a list of three elements:

• the field-name
• the field-type (pushbutton, radiobutton, checkbox, text, combobox, listbox, signature or unknown)
• the field-value Note that for a signature field, if a signature is present the returned field-value is simply the fixed string <<signature>>. Warning: field-names with accented characters or in general with non-ASCII charaters may require a special care when used. See the section Notes about field-names with accented letters for details.

pdfHandle field fieldname

return the field's value, or raise an error if fieldname is not a valid field. Warning: field-names with accented characters or in general with non-ASCII charaters may require a special care when used. See the section Notes about field-names with accented letters for details.

pdfHandle signatures

return a list of signature field-records . Each field-record is a list of two elements:

• the field-name
• the field-value Empty signature fields (blanc signatures) have a field-value equal to "" (empty string). Currently, filled signature fields are simply denoted with the fixed string <<signature>>.

pdfHandle haschanges

return 1 if pdfHandle has been changed, otherwise 0.

pdfHandle canbesavedincrementally

return 1 if pdfHandle can be saved in incremental-mode, otherwise 0.

pdfHandle export filename

save the current document and its changes in an alternative filename. Note that the target filename should be different from the original pdf-file related with pdfHandle and in general, different from the name of any pdf-file currently opened in this process. When a pdfHandle is closed (see mupdf::close), all the changes will be saved to its original pdf-file. (see also mupdf::quit for closing without saving changes).

pdfHandle portfolio list

return the list of the embedded files

psdHandle portfolio extract i ?-dir pathname? ?-as filename?

extract the i-th embedded file. ( i >= 0 ) If option -dir is not specified, the embedded file is saved in the current directory. If option -as is not specified, embedded file is saved with its original name

pdfHandle search needle ?-startpage pagenum? ?-max hits?

search the string needle starting from page-number pagenum (default is page 0) and returning up to hits results (default is 10). The result of search subcommand is a list of page-positions. Each page-positions is a list of two elements:

• the page-number
• a list with the 4 coords of the box enclosing the searched needle Next results can be retrived with the search..more subcommand.

pdfHandle search..more ?-max hits?

return a list of the next hits elements matching the last given needle. The result of search..more subcommand is a list of page-positions similar to the list returned by search.

pageHandle size

return the physical size of the page as a list of two decimal numbers. Note that page size is expressed in points, i.e. 1/72 inch.

pageHandle docref

return a reference to the related pdf-document as a pdfHandle

pageHandle pagenumber

return the pagenumber of pageHandler

pageHandle savePNG filename ?-zoom zoom? ?-from x0 y0 x1 y1?

render the page in a .png file named filename. With a default -zoom factor equal to 1.0, a page whose size is W x H points is rendered as a raster image of W x H pixels. If -zoom is specified, the resulting image size is scaled by a factor of zoom. By default the whole page is rendered; the -from option, allows you to render only a given rectangular area of the page. x0 y0 are the coords of the top-left corner and x1 y1 are for the bottom-right corner. These coords must be expressed in terms of the physical size of the page, i.e in points Note that if these coords lies outside of the page, only the intersection of this area with the page area is rendered.

  ...
  set page [$pdf getpage 0]   ;# 0 is the 1st page
  lassign [$page size] dx dy
   # save just the upper half of the page
  $page savePNG /mydir/page0.png -zoom 2.25 -from 0 0 $dx [expr $dy/2]
  mupdf::close $pdf

pageHandle saveImage image ?-zoom zoom? ?-from x0 y0 x1 y1? ?-to x0 y0?

render the page in an existing Tk's photo image. The width and/or height of image are unchanged if the user has set on it an explicit image width or height (with the -width and/or -height configuration options, respectively). About the -zoom and -from options, the same rules for the savePNG apply. Option -to allows you to place the resulting raster image at the x0 y0 coords of the destination image. By default, is -to 0.0 0.0 NOTE: this command is not available with the package mupdf-notk.

pageHandle addsigfield fieldname x0 y0 x1 y1

add a blank signature field in a rectangular box at coords x0 y0 x1 y1. fieldname must be unique among the existing field names.

pageHandle search needle ?-fromtop true/false? ?-max hits?

search the string needle in the current page and return up to hits positions (default is 10). By default search starts from top of the page. If you need to find then next hits, use option -fromtop false. The result of search subcommand is a list of positions. Each positions is a list with the 4 coords of the box enclosing the searched needle.

pageHandle images list ?-id imageID?

return a list of all the images contained in the page referred by pageHandle. The result of images list subcommand is a list of image-records. Each image-record is a list of six elements:

• image-ID (unique for each page)
• image's width (in pixel)
• image's height (in pixel)
• image's colorspace (e.g. DeviceRGB, ICCBased, ...)
• image's bit per component (number of color components may be inferred from colorspace)
• mask-flag : 1 means that the image has a pixel-mask (i.e. some transparent pixels) If option -id is present, the resulting list is limited to the image-record for imageID.

pageHandle images extract ?-id imageID? ?-dir pathname? ?-as pattern? ?-transparency boolean?

if option -id is specified, extract and save the image referred by imageID (see images list). If option -id is missing, all the images contained in a page are extracted and saved. If option -dir is not specified, images are saved in the current directory. If option -as is not specified, images are saved with a name derived from the default mupdf::imagenamesformat (see below), otherwise images are saved as pattern (for pattern rules see below for mupdf::imagenamesformat). if option -transparency is true, save the (semi)transparent pixels (if any), otherwise transparent pixels (if any) are rendered as white pixels. extract returns a list of extracted-records. Each extracted-record is a list of three elements:

• image-ID (unique for each page)
• image-name (pdf page's internal name)
• saved filename (empty string if the image was skipped (unknow format...))

mupdf::imagenamesformat ?pattern?

a pattern is a parametric filename specification similar to the format specification used by the C printf function. If pattern is not specified, return the currently defined default pattern. If pattern is specified, set the default pattern. When the "pageHandle images extract ..." command is called, all the images are saved with a filename based on a pattern (This pattern can be explicit, if option -as is present, or it can be implicit, based on the default mupdf::imagenamesformat). a pattern is a a simple filename specification (just the base-name, since the extension of the extracted images (png, jpg, ...) is automatically determined.) with zero or more special symbols like the following ones:

• %p : page number (first page is 1)
• %P : total number of pages
• %i : image number - images in a page are numbered starting from 1
• %I : total number of images (in the current page) Special symbols may also be written with a padding-specification like %5P; this notation means the the symbol %P should be padded as a 5-character string with leading '0's. If more than one image is extracted in a single operation, and pattern does not contain the %i symbol (the image number), then -%i is implicitely appended in order to avoid a filename collision. Assuming that the current page is the page 123 (i.e the 124th page), the following command

  $pageHandle images extract -as "IMG_%5p"

will generate IMG_00124-1.jpg, IMG_00124-2.jpg ..... (note: the file extension may be different)

  $pageHandle images extract -as "Z%5p(%2i)"

will generate Z00124(01).jpg, Z00124(02).jpg ..... (note: the file extension may be different)

mupdf::close handle

if handle refers to a pageHandle, close the page. if handle refers to a pdfHandle, close the pdf (updating its original pdf-file) and all its opened pages;

mupdf::quit pdfHandle

close the pdfHandle without saving the changes.

mupdf::isobject handle

return 1 if handle is a valid reference to a pdf or a page.

mupdf::type handle

return document or page if handle is a valid reference, else raise an error.

mupdf::documents

return a list of the currently opened pdfHandles

mupdf::documentnames

return a list of pdf-filenames currently opened (fully normalized filenames).

mupdf::isopen filename

check if filename is among the currently opened pdf-files.

mupdf::cli_passwordhelper ?helperProc?

get/set the helper procedure for shell-like applications. If helperProc is , then the default helper is re-set. See section Working with Password Protected Files.

mupdf::tk_passwordhelper ?helperProc?

get/set the helper procedure for applications with a Tk graphical interface. If helperProc is , then the default helper is re-set. See section Working with Password Protected Files.

mupdf::libinfo

return specific attributes of the underlying MuPdf libray as a list of keywords and their values. The provided keywords are:

version

The version of the underlying MuPDf library

..more to come ..

Working with Password Protected Files edit

You can open a password-protected PDF in a non-interactive or in an interactive way. With the first way, non-interactive way, you must provide in advance a password

  set pdf [mupdf::open book.pdf -password "123open"]

If password is wrong then an error is raised; other than looking at the error message, you can check for the errorcode: it should be MUPDF WRONGPASSWORD. Note that there's no distinction between owner's password and user's password; if you provide the right owner's password, the PDF is opened in owner-mode, if you provide the right user's password, the PDF is opened in user-mode. You can check if PDF has been opened in user-mode or owner-mode by calling the authentication command.

  set pdf [mupdf::open book.pdf -password "123open"]
   # if we are here, it means that password was OK
  set mode [$pdf authentication]
   # "none" means that book.pdf was not password-protected
   # "user" means that the supplyed password was the user's password
   # "owner" means ...

The second way , interactive way, does not require to provide an explicit password; if the PDF is password-protected, mupdf will ask for a password. Depending on the nature of your application (with or without Tk), mupdf will select and call a predefined (yet customizable) helper procedure. These predefined, built-in procedures can be changed with the mupdf::cli_passwordhelper or mupdf::tk_passwordhelper command.

   # template for a (shell-like) password-helper procedure
   proc mypswdhelper {filename} {
       ...  ask for a password ....
       .... get the password ....
       ....
       return $password    
   }
  mupdf::cli_passwordhelper mypswdhelper

   # template for a (GUI) password-helper procedure
   proc myGUIpswdhelper {filename} {
       ...  raise some popup ...
       ...  ask for a password ....
       .... get the password ...
       .... close the popup
       return $password    
   }
  mupdf::tk_passwordhelper myGUIpswdhelper

Removing protection from a password protected files edit

If you open a password-protected file and export it, then the resulting PDF is saved without pasword.

Notes about field-names with accented letters edit

Field-names returned by [pdfHandle fields] are not standard (Unicode) strings; they are binary string. For 'good plain' field names like "City", there is no difference: the returned binary-string and the literal (Unicode) string "City" are byte-by-byte identical" Now let's consider a field-name like this "Città" (italian term for "City"): the returned field name, even if it is represented like "Città", is not comparable with the literal Unicode string "Città", just because the former byte-array is made of 5 bytes (plus a '\0' string-terminator), whereas the unicode string is made of 6 bytes (plus a '\0' string-terminator). This may produce strange results when comparing these values, and in particular cases, it may cause the field subcommand to produce unexpected results. Let's try with this interactive example:

 ...
 set fields [$pdf fields]
  # let's suppose the 0-th returned record is about the field "Città" ....
 
  # try to get the field value:
 set value [$pdf field Città] ;#  -->  error !!!

  # Workaround: let's take back the fieldname from the $fields list ... 
 set fieldname [lindex $fields 0 0] ;# field name is the 0-th elem of the 0-th record
 puts "$fieldname"  ;# -->  Città
 set value [$pdf field $fieldname]  ;# -->  ...  ok

LImitations edit

Full support for portfolio management is still incomplete; commands for adding/removing/reordering embedded files will require a more robust mupdf-core implementation. Support for password management is still incomplete; currently you can open password-protected PDFs, remove passwords, but there's no way to add/change passwords.

KEYWORDS edit

pdf, photo

CATEGORY edit

pdf parsing and rendering

COPYRIGHT edit

 Copyright (c) 2017, by A.Buratti