README
¶
go-pngtext
Parse textual data from a PNG file.
Usage
This code opens a file image.png and prints all textual data stored in the file:
package main
import (
"fmt"
"log"
"os"
"github.com/jkawamoto/go-pngtext"
)
func main() {
r, err := os.Open("image.png")
if err != nil {
log.Fatalf("failed to open a file: %v", err)
}
defer func() {
if err := r.Close(); err != nil {
log.Fatalf("failed to close a file: %v", err)
}
}()
res, err := pngtext.ParseTextualData(r)
if err != nil {
log.Fatalf("failed to parse textual data: %v", err)
}
for _, v:= range res{
fmt.Printf("%v: %v\n", v.Keyword, v.Text)
}
}
License
This software is released under the MIT License, see LICENSE.
Documentation
¶
Overview ¶
Package pngtext provides function ParseTextualData that parses a PNG file and returns a list of textual data stored in the file.
To parse textual data, simply call ParseTextualData:
r, _ := os.Open("test.png")
defer r.Close()
res, _ := pngtext.ParseTextualData(r)
TextualDataList, which ParseTextualData returns as a result, is a list of TextualData but also implements Find function that helps you to get text data associated with a keyword. This returns TextualData of which keyword is Description:
res.Find("Description")
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
Functions ¶
This section is empty.
Types ¶
type TextualData ¶
type TextualData struct {
// Keyword of the textual data.
Keyword string
// Text string associated with the keyword
Text string
// LanguageTag indicates the human language used by the translated keyword and the text.
// Only iTXt chunk has this attribute.
LanguageTag string
// TranslatedKeyword is a translation of the keyword into the language indicated by the language tag.
// Only iTXt chunk has this attribute.
TranslatedKeyword string
}
TextualData defines attributes one chunk could have. See also: https://www.w3.org/TR/2003/REC-PNG-20031110/#11textinfo
type TextualDataList ¶
type TextualDataList []*TextualData
TextualDataList is a list of *TextualData that provides Find and implements sort.Interface.
func ParseTextualData ¶
func ParseTextualData(r io.Reader) (TextualDataList, error)
ParseTextualData reads PNG data from the given reader and parses textual data.
Example ¶
r, _ := os.Open("test.png")
defer r.Close()
res, _ := pngtext.ParseTextualData(r)
fmt.Println(res.Find("Text").Text)
Output: text data
func (TextualDataList) Find ¶
func (list TextualDataList) Find(keyword string) *TextualData
Find sequentially searches an item of which keyword matches the given one. Returns nil if not matches any item.
func (TextualDataList) Len ¶
func (list TextualDataList) Len() int
Len is the number of elements in the collection.
func (TextualDataList) Less ¶
func (list TextualDataList) Less(i, j int) bool
Less reports whether the element with index i must sort before the element with index j.
func (TextualDataList) Swap ¶
func (list TextualDataList) Swap(i, j int)
Swap swaps the elements with indexes i and j.
Source Files