[toimage] Set filename for single dicom to image

toimage/src/main.rs

@@ -10,7 +10,7 @@ use dicom_pixeldata::{ConvertOptions, PixelDecoder};
 use regex::Regex;
 use snafu::prelude::*;
 use snafu::ResultExt;
-use tracing::{error, info, Level};
+use tracing::{error, info, warn, Level};
 use walkdir::WalkDir;
 
 /// Convert a DICOM file into an image file
@@ -24,6 +24,12 @@ struct App {
     #[arg(short = 'o', long = "out-dir", default_value = ".")]
     out_dir: PathBuf,
 
+    /// Set a custom output file name for a single input file, if unset, the input file name will
+    /// be used with the extension replaced by the target format
+    /// The filename should not include the target format extension
+    #[arg(short = 'O', long)]
+    out_file_name: PathBuf,
+
     /// Target format of the output image file
     #[arg(short = 'f', long = "format", default_value = "png")]
     format: String,
@@ -90,6 +96,7 @@ fn main() -> Result<(), Error> {
     let App {
         files,
         out_dir,
+        out_file_name,
         format,
         all_frames,
         verbose,
@@ -116,11 +123,17 @@ fn main() -> Result<(), Error> {
         info!("Converting {} DICOM files to images", dicom_files.len());
     }
 
+    let mut custom_file_name: bool = !out_file_name.as_os_str().is_empty();
+    if dicom_files.len() > 1 && custom_file_name {
+        warn!("Output file name will be ignored for multiple input files");
+        custom_file_name = false;
+    }
+
     // compiled once as advised in https://docs.rs/regex/latest/regex/struct.Regex.html#method.new
     let filename_increment_regex = Regex::new(r"\(\d+\)")
         .whatever_context("Could not compile regex for filename increment")?;
 
-    for file in dicom_files.into_iter() {
+    for mut file in dicom_files.into_iter() {
         let obj = open_file(&file).context(OpenFileSnafu)?;
 
         let pixel = match obj.decode_pixel_data() {
@@ -187,6 +200,10 @@ fn main() -> Result<(), Error> {
                 }
             };
 
+            if custom_file_name {
+                file = out_file_name.clone();
+            }
+
             let mut image_path = match compute_image_path(&file, &out_dir, &format, frame_number, i)
             {
                 Ok(path) => path,