Create encode test

tests/encode_images.rs

@@ -0,0 +1,58 @@
+extern crate tiff;
+
+use tiff::ColorType;
+use tiff::decoder::{Decoder, DecodingResult, ifd::Tag, ifd::Value};
+use tiff::encoder::{TiffEncoder, Rational};
+
+use std::fs::File;
+
+
+#[test]
+fn encode_decode() {
+    let mut image_data = Vec::new();
+    for x in 0..100 {
+        for y in 0..100u8 {
+            let val = x + y;
+            image_data.push(val);
+            image_data.push(val);
+            image_data.push(val);
+        }
+    }
+    {
+        let file = std::fs::File::create("test.tiff").unwrap();
+        let mut tiff = TiffEncoder::new_le(file);
+
+        tiff.write_header().unwrap();
+
+        tiff.new_ifd().unwrap();
+        tiff.new_ifd_entry(Tag::ImageWidth, &[100u32][..]);
+        tiff.new_ifd_entry(Tag::ImageLength, &[100u32][..]);
+        tiff.new_ifd_entry(Tag::BitsPerSample, &[8u16,8,8][..]);
+        tiff.new_ifd_entry(Tag::Compression, &[1u16][..]);
+        tiff.new_ifd_entry(Tag::PhotometricInterpretation, &[2u16][..]);
+        tiff.new_ifd_entry(Tag::StripOffsets, &[0u32][..]);
+        tiff.new_ifd_entry(Tag::SamplesPerPixel, &[3u16][..]);
+        tiff.new_ifd_entry(Tag::RowsPerStrip, &[100u32][..]);
+        tiff.new_ifd_entry(Tag::StripByteCounts, &[0u32][..]);
+        tiff.new_ifd_entry(Tag::XResolution, &[Rational {n: 1, d: 1}][..]);
+        tiff.new_ifd_entry(Tag::YResolution, &[Rational {n: 1, d: 1}][..]);
+        tiff.new_ifd_entry(Tag::ResolutionUnit, &[1u16][..]);
+        tiff.finish_ifd().unwrap();
+
+        tiff.write_strip(&image_data).unwrap();
+    }
+    {
+        let file = File::open("test.tiff").unwrap();
+        let mut decoder = Decoder::new(file).unwrap();
+        assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(8));
+        assert_eq!(decoder.dimensions().unwrap(), (100, 100));
+        if let DecodingResult::U8(img_res) = decoder.read_image().unwrap() {
+            assert_eq!(image_data, img_res);
+        }
+        else {
+            panic!("Wrong data type");
+        }
+    }
+    
+    std::fs::remove_file("test.tiff").unwrap();
+}