mirror of
https://github.com/unidoc/unipdf.git
synced 2025-05-09 19:29:34 +08:00
Add the 1 bit component decoding to ccitt
This commit is contained in:
nkryuchkov
parent
43625d5c66
commit
7d95a552f6
428
main.go
Normal file
428
main.go
Normal file
@ -0,0 +1,428 @@
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package main
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import (
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"archive/zip"
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"fmt"
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"image/png"
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"os"
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unicommon "github.com/unidoc/unidoc/common"
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pdfcontent "github.com/unidoc/unidoc/pdf/contentstream"
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pdfcore "github.com/unidoc/unidoc/pdf/core"
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"github.com/unidoc/unidoc/pdf/creator"
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pdf "github.com/unidoc/unidoc/pdf/model"
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)
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/*func getPixels(file io.Reader) ([][]byte, error) {
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img, _, err := image.Decode(file)
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if err != nil {
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return nil, err
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}
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bounds := img.Bounds()
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w, h := bounds.Max.X, bounds.Max.Y
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var pixels [][]byte
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for y := 0; y < h; y++ {
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var row []byte
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for x := 0; x < w; x++ {
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r, g, b, _ := img.At(x, y).RGBA()
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if r == 65535 && g == 65535 && b == 65535 {
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// append white
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row = append(row, 1)
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} else {
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row = append(row, 0)
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}
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}
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pixels = append(pixels, row)
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}
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return pixels, nil
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}
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// sliceDiff compares two slices returning the first index of the different
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// elements pair. Returns -1 if the slices contain the same elements
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func slicesDiff(s1, s2 []byte) int {
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minLen := 0
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if len(s1) < len(s2) {
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minLen = len(s1)
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} else {
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minLen = len(s2)
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}
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for i := 0; i < minLen; i++ {
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if s1[i] != s2[i] {
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return i
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}
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}
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return -1
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}
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func main() {
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image.RegisterFormat("png", "png", png.Decode, png.DecodeConfig)
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file, err := os.Open("/home/darkrengarius/Downloads/scan2.png")
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if err != nil {
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log.Fatalf("Error opening file: %v\n", err)
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}
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defer file.Close()
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pixels, err := getPixels(file)
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if err != nil {
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log.Fatalf("Error decoding the image: %v\n", err)
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}
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encoder := &ccitt.Encoder{BlackIs1: true}
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encoded := encoder.Encode(pixels)
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preparedBytes, err := ioutil.ReadFile("/home/darkrengarius/Downloads/scan2.gr3")
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if err != nil {
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log.Fatalf("Error opening gr3 file: %v\n", err)
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}
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log.Println(encoded)
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log.Println(preparedBytes)
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diffInd := slicesDiff(encoded, preparedBytes)
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if diffInd != -1 {
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log.Fatalf("Slices differ in %v. Encoded: %v, prepared: %v\n", diffInd,
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encoded[diffInd], preparedBytes[diffInd])
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}
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if len(encoded) != len(preparedBytes) {
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log.Fatalf("Slices differ in length")
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}
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log.Println("Slices are totally equal")
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}
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*/
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var xObjectImages = 0
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var inlineImages = 0
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func main() {
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// save images to pdf
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/*if err := imagesToPdf([]string{"/home/darkrengarius/Downloads/scan2.png"}, "/home/darkrengarius/Downloads/testCombined2232.pdf"); err != nil {
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log.Fatalf("Error writing images to pdf: %v\n", err)
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}*/
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// extract images from pdf to zip
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inputPath := "/home/darkrengarius/Downloads/000444.pdf"
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outputPath := "/home/darkrengarius/Downloads/000444_2.zip"
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fmt.Printf("Input file: %s\n", inputPath)
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err := extractImagesToArchive(inputPath, outputPath)
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if err != nil {
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fmt.Printf("Error: %v\n", err)
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os.Exit(1)
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}
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fmt.Printf("-- Summary\n")
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fmt.Printf("%d XObject images extracted\n", xObjectImages)
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fmt.Printf("%d inline images extracted\n", inlineImages)
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fmt.Printf("Total %d images\n", xObjectImages+inlineImages)
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}
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/*func imagesToPdf(inputPaths []string, outputPath string) error {
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c := creator.New()
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for _, imgPath := range inputPaths {
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unicommon.Log.Debug("Image: %s", imgPath)
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file, err := os.Open(imgPath)
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if err != nil {
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log.Fatalf("Error opening file: %v\n", err)
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}
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imgF, _, err := image.Decode(file)
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if err != nil {
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file.Close()
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return err
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}
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file.Close()
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modelImg, err := pdf.ImageHandling.NewImageFromGoImage(imgF)
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if err != nil {
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unicommon.Log.Debug("Error loading image: %v", err)
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return err
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}
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modelImg.BitsPerComponent = 1
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modelImg.ColorComponents = 1
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img, err := creator.NewImage(modelImg)
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if err != nil {
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unicommon.Log.Debug("Error loading image: %v", err)
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return err
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}
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img.ScaleToWidth(612.0)
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// Use page width of 612 points, and calculate the height proportionally based on the image.
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// Standard PPI is 72 points per inch, thus a width of 8.5"
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height := 612.0 * img.Height() / img.Width()
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c.SetPageSize(creator.PageSize{612, height})
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c.NewPage()
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img.SetPos(0, 0)
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enc := pdfcore.NewCCITTFaxEncoder()
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enc.K = -4
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enc.Columns = int(modelImg.Width)
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enc.EndOfBlock = true
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enc.EndOfLine = true
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img.SetEncoder(enc)
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_ = c.Draw(img)
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}
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err := c.WriteToFile(outputPath)
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return err
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}*/
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// Images to PDF.
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func imagesToPdf(inputPaths []string, outputPath string) error {
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c := creator.New()
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for _, imgPath := range inputPaths {
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unicommon.Log.Debug("Image: %s", imgPath)
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img, err := c.NewImageFromFile(imgPath)
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if err != nil {
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unicommon.Log.Debug("Error loading image: %v", err)
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return err
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}
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img.ScaleToWidth(612.0)
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// Use page width of 612 points, and calculate the height proportionally based on the image.
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// Standard PPI is 72 points per inch, thus a width of 8.5"
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height := 612.0 * img.Height() / img.Width()
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c.SetPageSize(creator.PageSize{612, height})
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c.NewPage()
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img.SetPos(0, 0)
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_ = c.Draw(img)
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}
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err := c.WriteToFile(outputPath)
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return err
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}
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// Extracts images and properties of a PDF specified by inputPath.
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// The output images are stored into a zip archive whose path is given by outputPath.
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func extractImagesToArchive(inputPath, outputPath string) error {
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f, err := os.Open(inputPath)
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if err != nil {
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return err
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}
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defer f.Close()
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pdfReader, err := pdf.NewPdfReader(f)
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if err != nil {
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return err
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}
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isEncrypted, err := pdfReader.IsEncrypted()
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if err != nil {
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return err
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}
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// Try decrypting with an empty one.
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if isEncrypted {
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auth, err := pdfReader.Decrypt([]byte(""))
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if err != nil {
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// Encrypted and we cannot do anything about it.
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return err
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}
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if !auth {
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fmt.Println("Need to decrypt with password")
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return nil
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}
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}
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numPages, err := pdfReader.GetNumPages()
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if err != nil {
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return err
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}
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fmt.Printf("PDF Num Pages: %d\n", numPages)
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// Prepare output archive.
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zipf, err := os.Create(outputPath)
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if err != nil {
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return err
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}
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defer zipf.Close()
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zipw := zip.NewWriter(zipf)
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for i := 0; i < numPages; i++ {
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fmt.Printf("-----\nPage %d:\n", i+1)
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page, err := pdfReader.GetPage(i + 1)
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if err != nil {
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return err
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}
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// List images on the page.
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rgbImages, err := extractImagesOnPage(page)
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if err != nil {
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return err
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}
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_ = rgbImages
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for idx, img := range rgbImages {
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fname := fmt.Sprintf("p%d_%d.png", i+1, idx)
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gimg, err := img.ToGoImage()
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if err != nil {
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return err
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}
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imgf, err := zipw.Create(fname)
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if err != nil {
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return err
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}
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err = png.Encode(imgf, gimg)
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if err != nil {
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return err
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}
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}
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}
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// Make sure to check the error on Close.
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err = zipw.Close()
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if err != nil {
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return err
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}
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return nil
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}
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func extractImagesOnPage(page *pdf.PdfPage) ([]*pdf.Image, error) {
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contents, err := page.GetAllContentStreams()
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if err != nil {
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return nil, err
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}
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return extractImagesInContentStream(contents, page.Resources)
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}
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func extractImagesInContentStream(contents string, resources *pdf.PdfPageResources) ([]*pdf.Image, error) {
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rgbImages := []*pdf.Image{}
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cstreamParser := pdfcontent.NewContentStreamParser(contents)
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operations, err := cstreamParser.Parse()
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if err != nil {
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return nil, err
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}
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processedXObjects := map[string]bool{}
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// Range through all the content stream operations.
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for _, op := range *operations {
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if op.Operand == "BI" && len(op.Params) == 1 {
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// BI: Inline image.
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iimg, ok := op.Params[0].(*pdfcontent.ContentStreamInlineImage)
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if !ok {
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continue
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}
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img, err := iimg.ToImage(resources)
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if err != nil {
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return nil, err
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}
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cs, err := iimg.GetColorSpace(resources)
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if err != nil {
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return nil, err
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}
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if cs == nil {
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// Default if not specified?
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cs = pdf.NewPdfColorspaceDeviceGray()
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}
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fmt.Printf("Cs: %T\n", cs)
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rgbImg, err := cs.ImageToRGB(*img)
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if err != nil {
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return nil, err
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}
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rgbImages = append(rgbImages, &rgbImg)
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inlineImages++
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} else if op.Operand == "Do" && len(op.Params) == 1 {
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// Do: XObject.
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name := op.Params[0].(*pdfcore.PdfObjectName)
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// Only process each one once.
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_, has := processedXObjects[string(*name)]
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if has {
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continue
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}
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processedXObjects[string(*name)] = true
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_, xtype := resources.GetXObjectByName(*name)
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if xtype == pdf.XObjectTypeImage {
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fmt.Printf(" XObject Image: %s\n", *name)
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ximg, err := resources.GetXObjectImageByName(*name)
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if err != nil {
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return nil, err
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}
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img, err := ximg.ToImage()
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if err != nil {
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return nil, err
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}
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img.ColorComponents = 3
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img.BitsPerComponent = 8
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goimg, err := img.ToGoImage()
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if err != nil {
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return nil, err
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}
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f, err := os.Create("/home/darkrengarius/Downloads/testDECODED.png")
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if err != nil {
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return nil, err
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}
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defer f.Close()
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err = png.Encode(f, goimg)
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if err != nil {
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return nil, err
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}
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cs := ximg.ColorSpace
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if cs == nil {
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// Default if not specified?
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cs = pdf.NewPdfColorspaceDeviceGray()
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}
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cs = pdf.NewPdfColorspaceDeviceRGB()
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fmt.Printf("Cs: %T\n", cs)
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rgbImg, err := cs.ImageToRGB(*img)
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if err != nil {
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return nil, err
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}
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rgbImages = append(rgbImages, &rgbImg)
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xObjectImages++
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} else if xtype == pdf.XObjectTypeForm {
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// Go through the XObject Form content stream.
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xform, err := resources.GetXObjectFormByName(*name)
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if err != nil {
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return nil, err
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}
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formContent, err := xform.GetContentStream()
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if err != nil {
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return nil, err
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}
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// Process the content stream in the Form object too:
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formResources := xform.Resources
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if formResources == nil {
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formResources = resources
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}
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// Process the content stream in the Form object too:
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formRgbImages, err := extractImagesInContentStream(string(formContent), formResources)
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if err != nil {
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return nil, err
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}
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rgbImages = append(rgbImages, formRgbImages...)
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}
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}
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}
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return rgbImages, nil
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}
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@ -1798,6 +1798,44 @@ func (this *CCITTFaxEncoder) DecodeBytes(encoded []byte) ([]byte, error) {
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return nil, err
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}
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//decoded := make([]byte, int(math.Ceil(float64(float64(len(pixels)*len(pixels[0]))/8.0))))
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/*var decoded []byte
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decodedIdx := 0
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var bitPos byte = 0
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var currentByte byte = 0
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for i := range pixels {
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for j := range pixels[i] {
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currentByte |= pixels[i][j] << (7 - bitPos)
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bitPos++
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if bitPos == 8 {
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decoded = append(decoded, currentByte)
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//decoded[decodedIdx] = currentByte
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currentByte = 0
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decodedIdx++
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bitPos = 0
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}
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}
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/*if bitPos > 0 {
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decoded = append(decoded, currentByte)
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currentByte = 0
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decodedIdx++
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bitPos = 0
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}*/
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/*}
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if bitPos > 0 {
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decoded = append(decoded, currentByte)
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//decoded[decodedIdx] = currentByte
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}*/
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decoded := make([]byte, len(pixels)*len(pixels[0])*3)
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decodedInd := 0
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