diff --git a/.gitignore b/.gitignore
index c575e89..78db5a8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,9 +9,10 @@ Cargo.lock
 # These are backup files generated by rustfmt
 **/*.rs.bk
 
-/img
-
+# images
 *.bmp
+*.png
+*.jpg
 
 # frave data format
 *.frv
diff --git a/img/decomposition.gif b/img/decomposition.gif
new file mode 100644
index 0000000..a52b4ac
Binary files /dev/null and b/img/decomposition.gif differ
diff --git a/src/commands.rs b/src/commands.rs
index 6456f9d..1b29b2e 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -13,7 +13,7 @@ pub fn encode(path: PathBuf, var: Variant, output: String) {
 
     let mut enc = FractalImage::new_from_img(img.into_luma8(), var);
     enc.find_coef();
-    // enc.quantizate(&get_quantization_matrix());
+    enc.quantizate(&get_quantization_matrix());
     let (coef, contexts) = enc.ans_encode();
     let compressed = Frv::new(enc.height, enc.width, contexts, var, coef);
     let mut f = File::create(output).unwrap_or_else(|e| panic!("Failed to encode frv image: {e}"));
@@ -27,7 +27,7 @@ pub fn decode(path: PathBuf, output: String) {
     let frv_img: Frv = bincode::deserialize_from(img).unwrap();
     let mut dec = FractalImage::new_from_frv(&frv_img);
     dec.ans_decode(frv_img.data, frv_img.ans_contexts);
-    // dec.unquantizate(&get_quantization_matrix());
+    dec.unquantizate(&get_quantization_matrix());
     dec.find_val();
     dec.image.save(output).unwrap_or_else(|e| {
         panic!("Failed to decode frv image: {e}");
diff --git a/src/compression/decoder.rs b/src/compression/decoder.rs
index b69dbb3..ce7ce5d 100644
--- a/src/compression/decoder.rs
+++ b/src/compression/decoder.rs
@@ -1,12 +1,14 @@
 use std::collections::HashMap;
 
+use itertools::Itertools;
 use rans::b64_decoder::B64RansDecoderMulti;
 use rans::RansDecoderMulti;
 
 use crate::compression::ans::{self, AnsContext};
 use crate::fractal::image::FractalImage;
-use crate::utils::bitwise;
-use crate::utils::coordinate::Coord;
+use crate::utils::{self, Coord};
+
+use super::encoder::Encoder;
 
 pub trait Decoder {
     /// Entropy decoding step of decoder procedure.
@@ -35,7 +37,7 @@ impl Decoder for FractalImage {
             .iter()
             .enumerate()
             .map(|(i, coefficient)| {
-                let layer = bitwise::get_prev_power_two(i + 1).trailing_zeros();
+                let layer = utils::get_prev_power_two(i + 1).trailing_zeros();
                 (*coefficient).map(|s| s * quantization_matrix[layer as usize])
             })
             .collect::<Vec<Option<i32>>>();
@@ -66,16 +68,19 @@ impl Decoder for FractalImage {
     }
 
     fn ans_decode(&mut self, compressed_coef: Vec<u8>, ans_contexts: Vec<AnsContext>) {
-        let mut coef = vec![];
-        let depth = self.depth;
+        self.find_coef();
+        let length = self.coef.iter().filter(|x| x.is_some()).count();
+        let mut coef = self.coef.clone();
+        let depth = utils::get_prev_power_two(length).trailing_zeros() + 1;
         let scale_bits = u32::try_from(depth - 1).unwrap();
         let mut decoder: B64RansDecoderMulti<3> = B64RansDecoderMulti::new(compressed_coef);
         let ctxs = ans_contexts;
         let layers = vec![
-            0..(1 << (depth - 2)),
-            (1 << (depth - 2))..(1 << (depth - 1)),
-            (1 << (depth - 1))..(1 << depth),
+            0..1 << (depth - 2),
+            1 << (depth - 2)..1 << (depth - 1),
+            1 << (depth - 1)..length,
         ];
+        let mut last = 0;
         for (i, layer) in layers.iter().enumerate() {
             let mut cum_freqs = ans::cum_sum(&ctxs[2 - i].freq);
             let cum_freq_to_symbols = ans::freqs_to_dec_symbols(&cum_freqs, &ctxs[2 - i].freq);
@@ -93,9 +98,15 @@ impl Decoder for FractalImage {
                 let symbol = symbol_map[&cum_freq_decoded];
                 decoder.advance_step_at(i, &cum_freq_to_symbols[&cum_freq_decoded], scale_bits);
                 decoder.renorm_at(i);
-                coef.push(Some(symbol));
+                last = insert_after_none_starting_from(symbol, last, &mut coef);
             }
         }
         self.coef = coef;
     }
 }
+
+fn insert_after_none_starting_from(element: i32, i: usize, vec: &mut Vec<Option<i32>>) -> usize {
+    let ind = (i..vec.len()).find(|j| vec[*j].is_some()).unwrap();
+    vec[ind] = Some(element);
+    ind + 1
+}
diff --git a/src/compression/encoder.rs b/src/compression/encoder.rs
index 02a7ff9..e184583 100644
--- a/src/compression/encoder.rs
+++ b/src/compression/encoder.rs
@@ -7,8 +7,7 @@ use rans::RansEncoderMulti;
 
 use crate::compression::ans::{self, AnsContext};
 use crate::fractal::image::FractalImage;
-use crate::utils::bitwise;
-use crate::utils::coordinate::Coord;
+use crate::utils::{self, Coord};
 
 fn try_apply<T: Copy>(first: Option<T>, second: Option<T>, operation: fn(T, T) -> T) -> Option<T> {
     match (first, second) {
@@ -55,7 +54,7 @@ impl Encoder for FractalImage {
         );
         self.coef[1] = try_apply(rt, lt, |r, l| (r - l) / 2);
         self.coef[0] = try_apply(rt, lt, |r, l| (r + l) / 2);
-        dbg!(self.coef.iter().filter(|x| x.is_some()).count());
+        // dbg!(self.coef.iter().filter(|x| x.is_some()).count());
     }
 
     fn fn_cf(&mut self, cn: Coord, ps: usize, dp: usize) -> Option<i32> {
@@ -78,24 +77,24 @@ impl Encoder for FractalImage {
             .iter()
             .enumerate()
             .map(|(i, coefficient)| {
-                let layer = bitwise::get_prev_power_two(i + 1).trailing_zeros();
+                let layer = utils::get_prev_power_two(i + 1).trailing_zeros();
                 (*coefficient).map(|s| s / quantization_matrix[layer as usize])
             })
             .collect::<Vec<Option<i32>>>();
     }
 
     fn ans_encode(&self) -> (Vec<u8>, Vec<AnsContext>) {
-        dbg!(&self.coef);
-        let layer1 = &self.coef[1 << (self.depth - 1)..];
-        let layer2 = &self.coef[1 << (self.depth - 2)..1 << (self.depth - 1)];
-        let layer3 = &self.coef[..1 << (self.depth - 2)];
+        let valid_coef = &self.coef.clone().into_iter().flatten().collect::<Vec<i32>>();
+        let true_depth = utils::get_prev_power_two(valid_coef.len()).trailing_zeros() + 1;
+        let layer1 = &valid_coef[1 << (true_depth - 1)..];
+        let layer2 = &valid_coef[1 << (true_depth - 2)..1 << (true_depth - 1)];
+        let layer3 = &valid_coef[..1 << (true_depth - 2)];
 
-        let mut encoder: B64RansEncoderMulti<3> = B64RansEncoderMulti::new(1 << self.depth);
+        let mut encoder: B64RansEncoderMulti<3> = B64RansEncoderMulti::new(valid_coef.len());
         let mut contexts: Vec<ans::AnsContext> = vec![];
 
         for (i, layer) in [layer1, layer2, layer3].into_iter().enumerate() {
-            let some_layer = layer.iter().flatten();
-            let counter = some_layer.clone().counts();
+            let counter = layer.clone().into_iter().counts();
             let freq = counter
                 .values()
                 .map(|e| u32::try_from(*e).unwrap())
@@ -103,7 +102,7 @@ impl Encoder for FractalImage {
             let symbols = counter.keys().map(|e| **e).collect::<Vec<i32>>();
             let cdf = ans::cum_sum(&freq);
 
-            let symbol_map = ans::freqs_to_enc_symbols(&cdf, &freq, self.depth);
+            let symbol_map = ans::freqs_to_enc_symbols(&cdf, &freq, true_depth as usize);
 
             let cdf_map = counter
                 .clone()
@@ -111,7 +110,8 @@ impl Encoder for FractalImage {
                 .zip(cdf.clone())
                 .collect::<HashMap<&i32, u32>>();
 
-            some_layer
+            layer
+                .iter()
                 .rev()
                 .for_each(|s| encoder.put_at(i, &symbol_map[&cdf_map[s]]));
 
diff --git a/src/fractal/image.rs b/src/fractal/image.rs
index a6b637c..5632539 100644
--- a/src/fractal/image.rs
+++ b/src/fractal/image.rs
@@ -5,7 +5,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::compression::ans::AnsContext;
 use crate::fractal::variants::Variant;
-use crate::utils::coordinate::Coord;
+use crate::utils::Coord;
 
 #[derive(Serialize, Deserialize)]
 pub struct Frv {
@@ -99,7 +99,7 @@ impl FractalImage {
             .find(|&(_i, rw, rh)| img_w as i32 <= rw && img_h as i32 <= rh)
             .unwrap()
             .0
-            - 1
+            -1 
     }
 
     fn find_center(depth: usize, variant: [Coord; 30]) -> Coord {
@@ -124,7 +124,7 @@ impl FractalImage {
 
     #[inline]
     pub fn set_pixel(&mut self, x: i32, y: i32, v: i32) {
-        let (x, y) = (u32::try_from(x).unwrap(), u32::try_from(y).unwrap());
+        let (x, y) = (x as u32, y as u32);
         let gray = v.clamp(0, 255) as u8;
         if x < self.width && y < self.height {
             self.image.put_pixel(x, y, image::Luma([gray]));
@@ -140,6 +140,6 @@ pub fn get_quantization_matrix_soft() -> Vec<i32> {
 #[must_use]
 pub fn get_quantization_matrix() -> Vec<i32> {
     vec![
-        1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 5, 9, 2,
+        1, 1, 1,1,1,1,1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 10, 10, 10, 10, 10, 16, 9, 2,
     ]
 }
diff --git a/src/fractal/variants.rs b/src/fractal/variants.rs
index 2264db9..dca861a 100644
--- a/src/fractal/variants.rs
+++ b/src/fractal/variants.rs
@@ -1,4 +1,4 @@
-use crate::utils::coordinate::Coord;
+use crate::utils::Coord;
 use clap::ValueEnum;
 use serde::{Deserialize, Serialize};
 
diff --git a/src/utils.rs b/src/utils.rs
new file mode 100644
index 0000000..d822c48
--- /dev/null
+++ b/src/utils.rs
@@ -0,0 +1,28 @@
+use std::ops;
+
+#[derive(Clone, Copy, Debug)]
+pub struct Coord {
+    pub x: i32,
+    pub y: i32,
+}
+
+impl ops::Add<Self> for Coord {
+    type Output = Self;
+    fn add(self, rhs: Self) -> Self::Output {
+        Self {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        }
+    }
+}
+
+pub const fn get_prev_power_two(x: usize) -> usize {
+    let mut num = x;
+    num |= num >> 1;
+    num |= num >> 2;
+    num |= num >> 4;
+    num |= num >> 8;
+    num |= num >> 16;
+
+    num ^ (num >> 1)
+}
diff --git a/src/utils/bitwise.rs b/src/utils/bitwise.rs
deleted file mode 100644
index 5eb2864..0000000
--- a/src/utils/bitwise.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-pub const fn get_prev_power_two(x: usize) -> usize {
-    let mut num = x;
-    num |= num >> 1;
-    num |= num >> 2;
-    num |= num >> 4;
-    num |= num >> 8;
-    num |= num >> 16;
-
-    num ^ (num >> 1)
-}
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
deleted file mode 100644
index d7fae66..0000000
--- a/src/utils/mod.rs
+++ /dev/null
@@ -1,2 +0,0 @@
-pub mod bitwise;
-pub mod coordinate;
diff --git a/src/utils/coordinate.rs b/utils.rs
similarity index 100%
rename from src/utils/coordinate.rs
rename to utils.rs