back_to_pdf flag implementation

src/go.mod

@@ -7,3 +7,5 @@ require (
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
 	golang.org/x/image v0.0.0-20220413100746-70e8d0d3baa9
 )
+
+require github.com/jung-kurt/gofpdf v1.16.2 // indirect

src/go.sum

@@ -1,8 +1,20 @@
+github.com/boombuler/barcode v1.0.0/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gen2brain/go-fitz v1.19.0 h1:tXuT5dpsxPNn7LS8eGv2uQ04EviyGb/o2AdEr1e4W0M=
 github.com/gen2brain/go-fitz v1.19.0/go.mod h1:UZAxMETTDK4UPpuh80HaRpPzgkSibUihXVzwj2ip5oQ=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
+github.com/jung-kurt/gofpdf v1.0.0/go.mod h1:7Id9E/uU8ce6rXgefFLlgrJj/GYY22cpxn+r32jIOes=
+github.com/jung-kurt/gofpdf v1.16.2 h1:jgbatWHfRlPYiK85qgevsZTHviWXKwB1TTiKdz5PtRc=
+github.com/jung-kurt/gofpdf v1.16.2/go.mod h1:1hl7y57EsiPAkLbOwzpzqgx1A30nQCk/YmFV8S2vmK0=
+github.com/phpdave11/gofpdi v1.0.7/go.mod h1:vBmVV0Do6hSBHC8uKUQ71JGW+ZGQq74llk/7bXwjDoI=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/ruudk/golang-pdf417 v0.0.0-20181029194003-1af4ab5afa58/go.mod h1:6lfFZQK844Gfx8o5WFuvpxWRwnSoipWe/p622j1v06w=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+golang.org/x/image v0.0.0-20190910094157-69e4b8554b2a/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.0.0-20220413100746-70e8d0d3baa9 h1:LRtI4W37N+KFebI/qV0OFiLUv4GLOWeEW5hn/KEJvxE=
 golang.org/x/image v0.0.0-20220413100746-70e8d0d3baa9/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

src/main.go

@@ -13,6 +13,7 @@ import (
 	"github.com/gen2brain/go-fitz"
 	"github.com/golang/freetype"
 	"github.com/golang/freetype/truetype"
+	"github.com/jung-kurt/gofpdf"
 	"golang.org/x/image/font/gofont/goregular"
 )
 
@@ -25,7 +26,7 @@ var (
 
 	extractionDirPath *string = flag.String(
 		"dst_dir",
-		"output_images",
+		"output",
 		"Specify path to the output directory",
 	)
 
@@ -46,6 +47,12 @@ var (
 		false,
 		"Add bottom space for a note or not",
 	)
+
+	backToPdf *bool = flag.Bool(
+		"back_to_pdf",
+		false,
+		"Convert extracted pages with a note back to pdf",
+	)
 )
 
 func addText(img *image.RGBA, x, y uint, text string, size float64) error {
@@ -72,7 +79,7 @@ func addText(img *image.RGBA, x, y uint, text string, size float64) error {
 
 func main() {
 	flag.Usage = func() {
-		fmt.Printf(`  -add_note_space
+		fmt.Printf(`  -add_note_space bool
         Add additional white bottom space below a note or not
   -dst_dir string
         Specify path to the output directory (default "output_images")
@@ -82,6 +89,8 @@ func main() {
         Set a note that will be added to the bottom of each extracted image
   -src_dir string
         Specify path to the directory where each found PDF file's pages will be converted to images (default ".")
+  -back_to_pdf bool
+  		Convert extracted pages with a note back to pdf
   
 (c) Kasyanov Nikolay Alexeyevich (Unbewohnte)
 `)
@@ -125,6 +134,19 @@ func main() {
 			continue
 		}
 
+		if *note == "" && *backToPdf {
+			fmt.Printf("No note was specified. No need to convert back to PDF !\n")
+			*backToPdf = false
+		}
+
+		customPDF := gofpdf.New("P", "pt", "A4", "")
+		customPDF.AddUTF8FontFromBytes("goregular", "", goregular.TTF)
+		customPDF.SetFont("goregular", "", 15)
+		err = customPDF.Error()
+		if err != nil {
+			fmt.Printf("Could not create a new custom PDF: %s\n", err)
+		}
+
 		for i := 0; i < pdf.NumPage(); i++ {
 			srcPDFImage, err := pdf.Image(i)
 			if err != nil {
@@ -132,9 +154,8 @@ func main() {
 				continue
 			}
 
-			outputImageFile, err := os.Create(
+			outputImageFilePath := filepath.Join(saveDirPath, strings.TrimSuffix(entryName, ".pdf")+fmt.Sprintf("_%d", i)+".png")
-				filepath.Join(saveDirPath,
+			outputImageFile, err := os.Create(outputImageFilePath)
-					strings.TrimSuffix(entryName, ".pdf")+fmt.Sprintf("_%d", i)+".png"))
 			if err != nil {
 				fmt.Printf("[%d] Could not create image file for %s page %d: %s\n", count, entryName, i, err)
 				continue
@@ -162,12 +183,40 @@ func main() {
 					continue
 				}
 
-				png.Encode(outputImageFile, newImage)
+				err = png.Encode(outputImageFile, newImage)
+				if err != nil {
+					fmt.Printf("[%d] Could not encode %s, page %d to png format: %s\n", count, entryName, i, err)
+					continue
+				}
+				outputImageFile.Sync()
+
+				if *backToPdf {
+					// customPDF.AddPage()
+					customPDF.AddPageFormat("P", gofpdf.SizeType{
+						Wd: float64(newImage.Bounds().Dx()),
+						Ht: float64(newImage.Bounds().Dy()),
+					})
+					pageW, pageH, _ := customPDF.PageSize(i)
+					//  := customPDF.GetPageSize()
+
+					customPDF.Image(outputImageFilePath, 0, 0, pageW, pageH, false, "", 0, "")
+				}
 			case false:
 				png.Encode(outputImageFile, srcPDFImage)
 			}
 
 			outputImageFile.Close()
 		}
+
+		if *note != "" && *backToPdf {
+			err = customPDF.OutputFileAndClose(
+				filepath.Join(saveDirPath, strings.TrimSuffix(entryName, ".pdf")+"_with_note.pdf"),
+			)
+			if err != nil {
+				fmt.Printf("Could not convert %s's pages back to pdf with a note: %s\n", entryName, err)
+			}
+		}
+
+		pdf.Close()
 	}
 }