1 files changed, 129 insertions, 0 deletions
diff --git a/pkg/hocr/hocr.go b/pkg/hocr/hocr.go
new file mode 100644
index 0000000..dcd0494
--- /dev/null
+++ b/pkg/hocr/hocr.go
@@ -0,0 +1,129 @@
+package hocr
+
+import (
+	"encoding/xml"
+	"errors"
+	"io/ioutil"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+type Hocr struct {
+	Lines []OcrLine `xml:"body>div>div>p>span"`
+}
+
+type OcrLine struct {
+	Class string    `xml:"class,attr"`
+	Id    string    `xml:"id,attr"`
+	Title string    `xml:"title,attr"`
+	Words []OcrWord `xml:"span"`
+	Text  string    `xml:",chardata"`
+}
+
+type OcrWord struct {
+	Class string    `xml:"class,attr"`
+	Id    string    `xml:"id,attr"`
+	Title string    `xml:"title,attr"`
+	Chars []OcrChar `xml:"span"`
+	Text  string    `xml:",chardata"`
+}
+
+type OcrChar struct {
+	Class string    `xml:"class,attr"`
+	Id    string    `xml:"id,attr"`
+	Title string    `xml:"title,attr"`
+	Chars []OcrChar `xml:"span"`
+	Text  string    `xml:",chardata"`
+}
+
+// Returns the confidence for a word based on its x_wconf value
+func wordConf(s string) (float64, error) {
+	re, err := regexp.Compile(`x_wconf ([0-9.]+)`)
+	if err != nil {
+		return 0.0, err
+	}
+	conf := re.FindStringSubmatch(s)
+	return strconv.ParseFloat(conf[1], 64)
+}
+
+func boxCoords(s string) ([4]int, error) {
+	var coords [4]int
+	re, err := regexp.Compile(`bbox ([0-9]+) ([0-9]+) ([0-9]+) ([0-9]+)`)
+	if err != nil {
+		return coords, err
+	}
+	coordstr := re.FindStringSubmatch(s)
+	for i := range coords {
+		c, err := strconv.Atoi(coordstr[i+1])
+		if err != nil {
+			return coords, err
+		}
+		coords[i] = c
+	}
+	return coords, nil
+}
+
+func noText(s string) bool {
+	t := strings.Trim(s, " \n")
+	return len(t) == 0
+}
+
+func Parse(b []byte) (Hocr, error) {
+	var hocr Hocr
+
+	err := xml.Unmarshal(b, &hocr)
+	if err != nil {
+		return hocr, err
+	}
+
+	return hocr, nil
+}
+
+func GetText(hocrfn string) (string, error) {
+	var s string
+
+	file, err := ioutil.ReadFile(hocrfn)
+	if err != nil {
+		return s, err
+	}
+
+	h, err := Parse(file)
+	if err != nil {
+		return s, err
+	}
+
+
+	for _, l := range h.Lines {
+		s += getLineText(l)
+	}
+	return s, nil
+}
+
+func GetAvgConf(hocrfn string) (float64, error) {
+	file, err := ioutil.ReadFile(hocrfn)
+	if err != nil {
+		return 0, err
+	}
+
+	h, err := Parse(file)
+	if err != nil {
+		return 0, err
+	}
+
+	var total, num float64
+	for _, l := range h.Lines {
+		for _, w := range l.Words {
+			c, err := wordConf(w.Title)
+			if err != nil {
+				return 0, err
+			}
+			total += c
+			num++
+		}
+	}
+	if num == 0 {
+		return 0, errors.New("No words found")
+	}
+	return total / num, nil
+}