only save when debugging

src/descriptors/dct.rs

@@ -40,7 +40,6 @@ impl DCT {
 
     fn dct(&self, img: image::DynamicImage) -> [f64; 64] {
         let mut dct_values: [f64; 64] = [0.0; 64];
-        img.save("resize.png").expect("Error saving file");
         for u in 0..8 {
             for v in 0..8 {
                 let k = (v*8)+u;
@@ -115,6 +114,7 @@ impl Descriptor for DCT {
         debug!("DCT-coefficients, quantized:\n {}", print_matrix(dct_values));
 
         if log_enabled!(Level::Debug) {
+            img.save("resize.png").expect("Error saving file");
             // De-quantization:
             for i in 0..64 {
                 dct_values[i] = dct_values[i] * self.quantization_matrix[i] as f64;