pico

package module
v0.0.0-...-0dddbe1 Latest Latest
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 Go to latest Published: Jul 28, 2023 License: MIT Imports: 18 Imported by: 0

README

pico - convert PDF to images with progress

A Go implementation for @Belval's Python pdf2image but with progress support.

convert with progress bar

Install package and dependency

$ go install github.com/DeathKing/pico/...@latest

NOTICE
this will also install the binary pdf2image in $GOPATH/bin folder.

Windows

Windows users will have to build or download poppler for Windows. I recommend @oschwartz10612 version which is the most up-to-date. You will then have to add the bin/ folder to PATH or use WithPopperPath("C:/path/to/poppler-xx/bin").

Mac

Mac users will have to install poppler.

Installing using Brew:

brew install poppler
Linux

Most distros ship with pdftoppm and pdftocairo. If they are not installed, refer to your package manager to install poppler-utils

Platform-independant (Using conda)

Install poppler: conda install -c conda-forge poppler

Usage

Programmatically use it as a library
import "github.com/DeathKing/pico"

func main() {

    // Case 1. Silently convert file with single worker, you must use `Wait()`
    //         for synchronization
    // see _example/single/main.go
    task, _ := pico.Convert("path/to/pdf")
    task.Wait()

    // Case 2. Convert single file with multiple worker, instead of `Wait()`
    //         for final result, we take the per-page conversion result through
    //         `Entries` channel. In this situation, `task.Wait()` is not a
    //         neccessary
    // see _example/woker/main.go
    task, _ = pico.Convert("path/to/pdf",
        pico.WithJob(4),
    )

    // entry is like ["current_page" "total_page" "output_filename" "worker_index"]
    for entry := range task.Entries {
		fmt.Printf("page %s is converted as file %s \n",
			entry[0], // current page
			entry[2], // output filename
		)
	}

    // Case 3. A more fancy usage
    task, _ = pico.Convert("path/to/pdf",
        pico.WithPopperPath("path/to/poppler"),
        pico.WithFormat("jpg"),
        pico.WithDPI(72),
        pico.WithPageRange(22, 42),             // Convert from Page 22 to Page 42 (included)
        pico.WithJob(3)                         // Using 3 worker/process to convert
        pico.WithTimeout(10 * time.Second)      // Must finished within 10 seconds
    )

    // `WaitAndCollect()` will blocked the excution and collect the conversion
    // result into a slice.
    for _, item := task.WaitAndCollect() {
        fmt.Printf("[worker#%d] file: %s %s/%s", entry[3], entry[2], entry[0], entry[1])
    }
}
Use it as a command line tool
df2image [-d dpi] [-f firstPage] [-l lastPage] [-j n] [-o outputFolder] path/to/file pattern/to/folder

For more detail , see cmd/pdf2image/main.go.

TODO

  • outputFileFn() to specify output filename by function.
  • Converts() function which support concurrently convert multiple files.
  • implement WithScale()/WithSize()/WithScaleToX()/WithScaleToY option
    • WithScale(400) or WithSize(400) will fit the image to a 400x400 box, preserving aspect ratio.
    • WithScaleToX(400) will make the image 400 pixels wide, preserving aspect ratio.
    • WithScaleToY(400) will make the image 400 pixels height, preserving aspect ratio.
  • explaining each parameters in detail.
  • more robust command line parsing.
  • more test cases.

Limitations / known issues

  1. Not working well with filename or path that contains CJK characters (this may caused by poppler).

Credit

Much thanks go to Edouard Belval for not only his original Python library pdf2image which inspires this Golang variation, but also the poppler installation instructions.

Documentation

Index

Constants

This section is empty.

Variables

View Source 
var ErrProviderClosed = errors.New("provider is closed")
View Source 
var WithSize = WithScaleTo

WithSize is the alias of WithScaleTo

Functions

func GetInfo 

func GetInfo(pdf string, options ...CallOption) (map[string]string, error)

func GetPagesCount 

func GetPagesCount(pdfPath string, options ...CallOption) (int, error)

Types

type BatchTask 

type BatchTask struct {
	Task
}

BatchTask deals with multiple documents conversion where each convertor converts single document.

func ConvertFiles 

func ConvertFiles(files interface{}, options ...CallOption) (*BatchTask, error)

ConvertFiles converts multiple PDF files to images

files could be type `[]string`, `chan string`, or `PdfProvider`

func (*BatchTask) Start 

func (t *BatchTask) Start(provider PdfProvider) error

type CallOption 

type CallOption func(o *Parameters, command []string) []string

func WithContext 

func WithContext(ctx context.Context) CallOption

func WithDpi 

func WithDpi(dpi int) CallOption

WithDpi sets image quality in DPI (default 200)

func WithFirstPage 

func WithFirstPage(firstPage int) CallOption

WithFirstPage sets the first page to convert

func WithFormat 

func WithFormat(fmt string) CallOption

WithFormat sets the output image format

func WithGrayScale 

func WithGrayScale() CallOption

func WithHideAnnotations 

func WithHideAnnotations() CallOption

func WithJPEGOpt 

func WithJPEGOpt(jpegOpt map[string]string) CallOption

func WithJPEGOptimize 

func WithJPEGOptimize(optimize bool) CallOption

func WithJPEGProgressive 

func WithJPEGProgressive(progressive bool) CallOption

func WithJPEGQuality 

func WithJPEGQuality(quality int) CallOption

func WithJob 

func WithJob(job int) CallOption

WithJob sets the number of threads to use

func WithLastPage 

func WithLastPage(lastPage int) CallOption

WithLastPage sets the last page to convert

func WithOutputFile 

func WithOutputFile(outputFile string) CallOption

func WithOutputFileFn 

func WithOutputFileFn(fn nameFn) CallOption

func WithOutputFolder 

func WithOutputFolder(outputFolder string) CallOption

Write the resulting images to a folder (instead of directly in memory)

func WithOwnerPw 

func WithOwnerPw(ownerPw string) CallOption

WithOwnerPw sets PDF's owner password

func WithPageRange 

func WithPageRange(firstPage, lastPage int) CallOption

WithPageRange sets the range of pages to convert

func WithPopplerPath 

func WithPopplerPath(popplerPath string) CallOption

WithPopplerPath sets poppler binaries lookup path

func WithScaleTo 

func WithScaleTo(size int) CallOption

WithScaleTo sets the size of the resulting images, size=400 will fit the image to a 400x400 box, preserving aspect ratio

func WithScaleToX 

func WithScaleToX(size int) CallOption

func WithScaleToY 

func WithScaleToY(size int) CallOption

func WithSingleFile 

func WithSingleFile() CallOption

func WithStrict 

func WithStrict() CallOption

WithStrict sets to strict mode, when a Syntax Error is thrown, it will be raised as an Exception

func WithTimeout 

func WithTimeout(timeout time.Duration) CallOption

WithTimeout

func WithTransparent 

func WithTransparent() CallOption

func WithUseCropBox 

func WithUseCropBox() CallOption

func WithUsePdftocario 

func WithUsePdftocario() CallOption

func WithUserPw 

func WithUserPw(userPw string) CallOption

WithUserPw sets PDF's password

func WithVerbose 

func WithVerbose() CallOption

WithVerbose will prints useful debugging information

type ChanProvider 

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

func (*ChanProvider) Count 

func (p *ChanProvider) Count() int

func (*ChanProvider) Source 

func (p *ChanProvider) Source() <-chan string

type ConversionError 

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

func (*ConversionError) Cause 

func (e *ConversionError) Cause() error

func (*ConversionError) Error 

func (e *ConversionError) Error() string

type Convertor 

type Convertor struct {
	Progress
	// contains filtered or unexported fields
}

func (*Convertor) Aborted 

func (c *Convertor) Aborted() bool

func (*Convertor) Completed 

func (c *Convertor) Completed() bool

Completed reports whether the convertor is in completed state

func (*Convertor) Error 

func (c *Convertor) Error() (err error)

func (*Convertor) Errors 

func (c *Convertor) Errors() []*ConversionError

type GetBinaryVersionError 

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

func NewGetBinaryVersionError 

func NewGetBinaryVersionError(binary string) *GetBinaryVersionError

func (*GetBinaryVersionError) Error 

func (e *GetBinaryVersionError) Error() string

type Observable 

type Observable interface {
	// Total is the total
	Total() int32

	// Finished counts finished conversion, since the conversion may be a
	// part of a file, like from `firstPage` to `lastPage`, thus the total
	// count may less than `lastPage` and Finished() <= Current() always holds
	Finished() int32

	// Current is the current page number we've just converted
	Current() int32

	Completed() bool
	Aborted() bool
}

type PDFSyntaxError 

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

func NewOldPDFSyntaxError 

func NewOldPDFSyntaxError(line, filename string, page int32) *PDFSyntaxError

func NewPDFSyntaxError 

func NewPDFSyntaxError(line string) *PDFSyntaxError

func (*PDFSyntaxError) Error 

func (e *PDFSyntaxError) Error() string

type Parameters 

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

type PdfProvider 

type PdfProvider interface {
	Source() <-chan string
	Count() int
}

func FromChan 

func FromChan(ch chan string) PdfProvider

func FromGlob 

func FromGlob(pattern string) PdfProvider

func FromInterface 

func FromInterface(i interface{}) PdfProvider

func FromMultiSource 

func FromMultiSource(patterns []string) PdfProvider

func FromMultiSourceAsync 

func FromMultiSourceAsync(patterns []string) PdfProvider

func FromSlice 

func FromSlice(files []string) PdfProvider

type PerPageTimeoutError 

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

func NewPerPageTimeoutError 

func NewPerPageTimeoutError(page string) *PerPageTimeoutError

func (*PerPageTimeoutError) Error 

func (e *PerPageTimeoutError) Error() string

type Progress 

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

func (*Progress) Current 

func (p *Progress) Current() int32

func (*Progress) Filename 

func (p *Progress) Filename() string

func (*Progress) Finished 

func (p *Progress) Finished() int32

func (*Progress) Incr 

func (p *Progress) Incr(delta int32)

func (*Progress) PushTotal 

func (p *Progress) PushTotal(delta int32)

func (*Progress) SetCurrent 

func (p *Progress) SetCurrent(current int32)

func (*Progress) Total 

func (p *Progress) Total() int32

type SingleTask 

type SingleTask struct {
	Task
}

SingleTask deals with single document conversion where usually the given pdf is a large file so we split it (evenly) into parts by page ranges and dispatch them to every convertor.

func Convert 

func Convert(pdf string, options ...CallOption) (*SingleTask, error)

Convert converts single PDF to images. This function is solely a options parser and command builder

func (*SingleTask) Start 

func (t *SingleTask) Start(pdf string) error

Start initiates the conversion process

type SliceFileProvider 

type SliceFileProvider struct {
	ChanProvider
	// contains filtered or unexported fields
}

func (*SliceFileProvider) Count 

func (p *SliceFileProvider) Count() int

type Task 

type Task struct {
	// FileProgress is measured by file counts
	Progress

	// Convertors are used to convert PDF to images
	Convertors []*Convertor

	// Entries is the channel of conversion progress entry
	// the format will be ["currentPage" "lastPage" "filename" "workerId"]
	Entries chan []string
	// contains filtered or unexported fields
}

func (*Task) Aborted 

func (t *Task) Aborted() bool

func (*Task) Completed 

func (t *Task) Completed() bool

func (*Task) Error 

func (t *Task) Error() error

func (*Task) Errors 

func (t *Task) Errors() (errs []*ConversionError)

func (*Task) Wait 

func (t *Task) Wait()

Wait hijacks the EntryChan and wait for all the workers finish

func (*Task) WaitAndCollect 

func (t *Task) WaitAndCollect() (entries [][]string)

WaitAndCollect acts like Wait() but collects all the entries into a slice. A empty array is returned if there is no entry received.

type WrongArgumentError 

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

func (*WrongArgumentError) Error 

func (e *WrongArgumentError) Error() string

Source Files

View all Source files

Directories

Path Synopsis
_example
batch
fancy
single
worker
cmd
pdf2image

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