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// For reading and opening files
use png::text_metadata::{ITXtChunk, ZTXtChunk};
use std::env;
use std::fs::File;
use std::io::BufWriter;
fn main() {
let path = env::args()
.nth(1)
.expect("Expected a filename to output to.");
let file = File::create(path).unwrap();
let w = &mut BufWriter::new(file);
let mut encoder = png::Encoder::new(w, 2, 1); // Width is 2 pixels and height is 1.
encoder.set_color(png::ColorType::Rgba);
encoder.set_depth(png::BitDepth::Eight);
// Adding text chunks to the header
encoder
.add_text_chunk(
"Testing tEXt".to_string(),
"This is a tEXt chunk that will appear before the IDAT chunks.".to_string(),
)
.unwrap();
encoder
.add_ztxt_chunk(
"Testing zTXt".to_string(),
"This is a zTXt chunk that is compressed in the png file.".to_string(),
)
.unwrap();
encoder
.add_itxt_chunk(
"Testing iTXt".to_string(),
"iTXt chunks support all of UTF8. Example: हिंदी.".to_string(),
)
.unwrap();
let mut writer = encoder.write_header().unwrap();
let data = [255, 0, 0, 255, 0, 0, 0, 255]; // An array containing a RGBA sequence. First pixel is red and second pixel is black.
writer.write_image_data(&data).unwrap(); // Save
// We can add a tEXt/zTXt/iTXt at any point before the encoder is dropped from scope. These chunks will be at the end of the png file.
let tail_ztxt_chunk = ZTXtChunk::new(
"Comment".to_string(),
"A zTXt chunk after the image data.".to_string(),
);
writer.write_text_chunk(&tail_ztxt_chunk).unwrap();
// The fields of the text chunk are public, so they can be mutated before being written to the file.
let mut tail_itxt_chunk = ITXtChunk::new("Author".to_string(), "सायंतन खान".to_string());
tail_itxt_chunk.compressed = true;
tail_itxt_chunk.language_tag = "hi".to_string();
tail_itxt_chunk.translated_keyword = "लेखक".to_string();
writer.write_text_chunk(&tail_itxt_chunk).unwrap();
}
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