package main import ( "bufio" "errors" "flag" "fmt" "log" "os" "path" "path/filepath" "sort" "strings" "rescribe.xyz/bookpipeline" ) const usage = `Usage: pdfbook [-c] [-s] dir out.pdf Creates a searchable PDF from a directory of hOCR and image files. If a 'best' file exists in the directory, each hOCR listed in it is used to provide the searchable text for each page. Otherwise pdfbook just looks for a .hocr with the same file base as the image for the searchable text. ` type Pdfer interface { Setup() error AddPage(imgpath, hocrpath string, smaller bool) error Save(path string) error } const pageWidth = 5 // pageWidth in inches // pxToPt converts a pixel value into a pt value (72 pts per inch) // This uses pageWidth to determine the appropriate value func pxToPt(i int) float64 { return float64(i) / pageWidth } // imgPath returns an appropriate path for the image that // corresponds with the hocrpath func imgPath(hocrpath string, colour bool) string { d := path.Dir(hocrpath) name := path.Base(hocrpath) nosuffix := strings.TrimSuffix(name, ".hocr") imgname := "" if colour { p := strings.SplitN(name, "_bin", 2) if len(p) > 1 { imgname = p[0] + ".jpg" } else { imgname = nosuffix + ".jpg" } } else { imgname = nosuffix + ".png" } return path.Join(d, imgname) } // addBest adds the pages in dir/best to a PDF func addBest(dir string, pdf Pdfer, colour, smaller bool) error { f, err := os.Open(path.Join(dir, "best")) if err != nil { log.Fatalln("Failed to open best file", err) } defer f.Close() s := bufio.NewScanner(f) var files []string for s.Scan() { fn := s.Text() if path.Ext(fn) != ".hocr" { continue } files = append(files, fn) } sort.Strings(files) for _, f := range files { hocrpath := path.Join(dir, f) img := imgPath(hocrpath, colour) err := pdf.AddPage(img, hocrpath, smaller) if err != nil { return errors.New(fmt.Sprintf("Failed to add page %s: %v", f, err)) } } return nil } // walker walks each hocr file in a directory and adds a page to // the pdf for each one. func walker(pdf Pdfer, colour, smaller bool) filepath.WalkFunc { return func(fpath string, info os.FileInfo, err error) error { if err != nil { return err } if info.IsDir() { return nil } if path.Ext(fpath) != ".hocr" { return nil } return pdf.AddPage(imgPath(fpath, colour), fpath, smaller) } } func main() { colour := flag.Bool("c", false, "colour") smaller := flag.Bool("s", false, "smaller") flag.Usage = func() { fmt.Fprintln(flag.CommandLine.Output(), usage) flag.PrintDefaults() } flag.Parse() if flag.NArg() != 2 { flag.Usage() return } pdf := new(bookpipeline.Fpdf) err := pdf.Setup() if err != nil { log.Fatalln("Failed to set up PDF", err) } _, err = os.Stat(path.Join(flag.Arg(0), "best")) if err != nil && !os.IsNotExist(err) { log.Fatalln("Failed to stat best", err) } if os.IsNotExist(err) { err = filepath.Walk(flag.Arg(0), walker(pdf, *colour, *smaller)) if err != nil { log.Fatalln("Failed to walk", flag.Arg(0), err) } } else { err = addBest(flag.Arg(0), pdf, *colour, *smaller) if err != nil { log.Fatalln("Failed to add best pages", err) } } err = pdf.Save(flag.Arg(1)) if err != nil { log.Fatalln("Failed to save", flag.Arg(1), err) } }