Improved memory efficiency of loading images

AlanRace · Nov 16, 2022 · a726029 · a726029
1 parent b691b23
commit a726029
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Showing 3 changed files with 19 additions and 12 deletions.
diff --git a/lib/Cargo.toml b/lib/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "imc-rs"
-version = "0.1.4"
+version = "0.1.5"
 edition = "2021"
 authors = ["Alan Race <alan.race@uni-marburg.de>"]
 homepage = "https://github.com/AlanRace/imc-rs"

diff --git a/lib/src/convert/mod.rs b/lib/src/convert/mod.rs
@@ -1,7 +1,7 @@
 use std::{
     collections::HashMap,
     fs::File,
-    io::{BufReader, BufWriter, Cursor, Read, Seek, SeekFrom, Write},
+    io::{BufReader, Cursor, Read, Seek, SeekFrom, Write},
     sync::{Arc, Mutex},
 };
 

diff --git a/lib/src/lib.rs b/lib/src/lib.rs
@@ -62,7 +62,7 @@ use std::collections::HashMap;
 use calibration::{Calibration, CalibrationChannel, CalibrationFinal, CalibrationParams};
 use mcd::{MCDParser, ParserState};
 
-use image::{DynamicImage, ImageFormat, RgbaImage};
+use image::{DynamicImage, ImageFormat, RgbImage, RgbaImage};
 use slide::{SlideFiducialMarks, SlideProfile};
 use transform::AffineTransform;
 
@@ -129,20 +129,27 @@ impl<R: Read + Seek> OpticalImage<R> {
 
     /// Returns a decoded RgbaImage of the panorama image
     pub fn as_rgba8(&self) -> Result<RgbaImage> {
-        // match self.dynamic_image()? {
-        //     DynamicImage::ImageRgba8(rgba8) => Ok(rgba8),
-        //     DynamicImage::ImageRgb8(rgb8) => Ok(DynamicImage::ImageRgb8(rgb8).into_rgba8()),
-        //     _ => panic!("Unexpected DynamicImage type"),
-        // }
         Ok(self.dynamic_image()?.into_rgba8())
     }
 
+    /// Returns a decoded RgbImage of the panorama image
+    pub fn as_rgb8(&self) -> Result<RgbImage> {
+        Ok(self.dynamic_image()?.into_rgb8())
+    }
+
     fn dynamic_image(&self) -> Result<DynamicImage> {
-        let mut reader = ImageReader::new(Cursor::new(self.image_data()?));
-        reader.set_format(self.image_format);
+        let mut reader = self.reader.lock().or(Err(MCDError::PoisonMutex))?;
+        let start_offset = self.start_offset();
 
-        // TODO: Deal with this error properly
-        Ok(reader.decode()?)
+        match reader.seek(SeekFrom::Start(start_offset as u64)) {
+            Ok(_seek) => {
+                let mut reader = ImageReader::new(reader.deref_mut());
+                reader.set_format(self.image_format);
+
+                Ok(reader.decode()?)
+            }
+            Err(error) => Err(error.into()),
+        }
     }
 }