diff --git a/README.md b/README.md
new file mode 100644
index 0000000..8d6c63d
--- /dev/null
+++ b/README.md
@@ -0,0 +1,7 @@
+<!-- vim: set spelllang=fr: -->
+
+# Utilisation d’un sonagramme pour retrouver les notes d’un enregistrement
+
+![](fig/synth-single.png)
+
+![](fig/synth-shorttime.png)
diff --git a/analyze-shorttime.py b/analyze-shorttime.py
index 88493fd..8ae7516 100644
--- a/analyze-shorttime.py
+++ b/analyze-shorttime.py
@@ -3,12 +3,30 @@ import numpy as np
 import scipy.signal as sig
 import matplotlib
 import matplotlib.pyplot as plt
+import sys
 
-signal = soundbox.load_signal('out.wav')
+if len(sys.argv) != 3:
+    print(f"""Utilisation: {sys.argv[0]} [source] [output]
 
+Génère le sonagramme du fichier [source] dans le fichier [output].""")
+    sys.exit(1)
+
+source_file = sys.argv[1]
+output_file = sys.argv[2]
+
+# Calcul du STFT
+signal = soundbox.load_signal(source_file)
 freq, time, fts = sig.stft(signal, soundbox.samp_rate, nperseg=soundbox.samp_rate * 0.5)
 
+# Génération du graphe
+plt.rcParams.update({
+    'figure.figsize': (8, 8),
+    'font.size': 16,
+    'font.family': 'Concourse T4',
+})
+
 fig, ax = plt.subplots()
+ax.tick_params(axis='both', which='major', labelsize=12)
 ax.pcolormesh(
     time, freq,
     np.abs(fts),
@@ -16,14 +34,14 @@ ax.pcolormesh(
     shading='gouraud')
 
 
-def freq_format(value, pos):
-    return f'{value:.0f} Hz'
-
-
 def time_format(value, pos):
     return f'{value:.0f} s'
 
 
+def freq_format(value, pos):
+    return f'{value:.0f} Hz'
+
+
 ax.set_xlabel('Temps')
 ax.xaxis.set_major_formatter(matplotlib.ticker.FuncFormatter(time_format))
 
@@ -31,4 +49,6 @@ ax.set_ylabel('Fréquence')
 ax.set_ylim(0, 800)
 ax.yaxis.set_major_formatter(matplotlib.ticker.FuncFormatter(freq_format))
 
-plt.show()
+# Sauvegarde comme image
+plt.tight_layout()
+plt.savefig(output_file)
diff --git a/analyze-single.py b/analyze-single.py
index 9635bb2..c61ca72 100644
--- a/analyze-single.py
+++ b/analyze-single.py
@@ -2,22 +2,54 @@ import soundbox
 import numpy as np
 import matplotlib
 import matplotlib.pyplot as plt
+import sys
 
-signal = soundbox.load_signal('out.wav')
+if len(sys.argv) != 3:
+    print(f"""Utilisation: {sys.argv[0]} [source] [output]
+
+Affiche la transformée de Fourier du fichier [source] sur un graphe
+dans le fichier [output].""")
+    sys.exit(1)
+
+source_file = sys.argv[1]
+output_file = sys.argv[2]
+
+# Calcul du FFT
+signal = soundbox.load_signal(source_file)
 freqs = np.fft.fft(signal)
-scale = soundbox.samp_rate / len(signal)
+
+# Génération du graphe
+ampl_scale = 1 / np.max(np.absolute(freqs))
+freq_scale = soundbox.samp_rate / len(signal)
+
+plt.rcParams.update({
+    'figure.figsize': (8, 4),
+    'font.size': 16,
+    'font.family': 'Concourse T4',
+})
 
 fig, ax = plt.subplots()
+ax.tick_params(axis='both', which='major', labelsize=12)
 ax.plot(np.absolute(freqs))
 
 
 def freq_format(value, pos):
-    return f'{value * scale:.0f} Hz'
+    return f'{value * freq_scale:.0f} Hz'
+
+
+def ampl_format(value, pos):
+    return f'{value * ampl_scale:.1f}'
 
 
 ax.set_xlabel('Fréquence')
-ax.set_xlim(0 / scale, 800 / scale)
+ax.set_xlim(0 / freq_scale, 800 / freq_scale)
 ax.xaxis.set_major_formatter(matplotlib.ticker.FuncFormatter(freq_format))
-ax.xaxis.set_major_locator(plt.MultipleLocator(100 / scale))
+ax.xaxis.set_major_locator(plt.MultipleLocator(100 / freq_scale))
 
-plt.show()
+ax.set_ylabel('Amplitude')
+ax.yaxis.set_major_formatter(matplotlib.ticker.FuncFormatter(ampl_format))
+ax.yaxis.set_major_locator(plt.MultipleLocator(.2 / ampl_scale))
+
+# Sauvegarde comme image
+plt.tight_layout()
+plt.savefig(output_file)
diff --git a/fig/synth-shorttime.png b/fig/synth-shorttime.png
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diff --git a/fig/synth-single.png b/fig/synth-single.png
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diff --git a/sounds/synth.wav b/sounds/synth.wav
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