From 2d74094dc3e19b63c8a53f246efd302c80e13279 Mon Sep 17 00:00:00 2001
From: AdrienCos <ad.cosson@gmail.com>
Date: Thu, 6 Jun 2019 21:59:25 -0400
Subject: [PATCH] Fixed steganalysis parity to be compatible with RGBA images

---
 stegano/steganalysis/parity.py         |   2 +-
 tests/expected-results/parity_rgba.png | Bin 0 -> 2442 bytes
 tests/test_steganalysis.py             |   9 +++++++++
 3 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 tests/expected-results/parity_rgba.png

diff --git a/stegano/steganalysis/parity.py b/stegano/steganalysis/parity.py
index 0dfb3ac..6034664 100644
--- a/stegano/steganalysis/parity.py
+++ b/stegano/steganalysis/parity.py
@@ -31,7 +31,7 @@ def steganalyse(img: Image.Image) -> Image.Image:
     """
     Steganlysis of the LSB technique.
     """
-    encoded: Image.Image = img.copy()
+    encoded = Image.new(img.mode, (img.size))
     width, height = img.size
     for row in range(height):
         for col in range(width):
diff --git a/tests/expected-results/parity_rgba.png b/tests/expected-results/parity_rgba.png
new file mode 100644
index 0000000000000000000000000000000000000000..a1cf2afcaed9517a96a49610a3a676e84678a143
GIT binary patch
literal 2442
zcmb`}Yd8}O8wc=tddnO#QqC<=L{>RPZ4PP0%4r!gtdhveL}BbDwW%bE$zfx1$Yx`b
za}Lvl#*iH6P))JN=`j|)dmVb}%lrBL@O-(i-<SK#|GMt~btk#II_{L$k_P|)I}uLs
z3jlx&_?N?hJATb=I{ZZdKn{t3pF-ht7xU&bi;We}lB;GmFP#v{eo0|mzQHVBqgk3y
zdOl9;4&LSN33mnn{*W#W>;SYb-4g@st$`o_iTHm&@@r?J!#_H=H0jYNlm-C*WIrq@
zz$#>W`nG&7AC4M0gK~KXM|Ccwk<i+Tv-dy+h3SI^4NF99>LXnk;4^WnR~7pJSmXR-
zoDXOI2XW@i&5E?ph4VXG)sK<Hj6dTeI#e{s;a7tbtn3-v0YXLLGAs!KEBSU{cCJxc
z6|42Bte7bg#guU2XNFe5>$H*n$}=X=+frb|LhZ5e5Y|glY-P>K-UdjJ9;Mr)DtT`3
z;SC-!^3JgBz!sXj6nQ;9N~x~;=}Wb2g)yn?(|KWNhMH#P$I9XFmO|#$Y}dHXu4+-q
zJB#cKQ?q3eo))0E&xH*n6QzST(>S(>IQ>p9Z^vdOggj&rfV=Mk%7WW?IDQ<o)jl1S
z6~IULU&!|!7j0~)Q<cbi_IPyH#mI%~pU0`qZ?He^l<+8dhga4{V?PCc5(uU~dk~^v
z^i?0oF!heFM^+Tp!)<R~t(%}Wd~@V&!cW3_^++40u}Q_D{Jc)|^Z!1kCx^R7uSpUD
zjAy=&UP})3;h76YtBr7LerU(5Z9xQrou^}aEqRG0=uM=f<UXR1hK@f^uUnWtn0W-`
zO~<3W_S(C^UE0-bJiGIo)ST7V_jGdR@*4-%Q{_rLTnkGp!rJ!xE|?3hl};4Z$gv^G
zW|A0h*&k~JW~$a$XHC#Si(a2Q^}#laR|PHKM=HB#IQs1dBsAojwP!W>#b#Ea@pnPE
zs7{!Yd2N-If(2b6Jm`){Uz{}XUj6di9J0=t#!EQUosyGia1|~;{T613smkSp1<T7z
z*nOPpnnnG4owpNt#8E$tZ?qK;(Xl-?-qSPuWX(d(s~&<${E)@h0Gq7vrDrswaU^71
zxgv!XnGt1+%dh#9;Y-IbXH1$S8sg%WBVc)aqu#at48yXj#xUIOey`Ne4;T62o@v;a
zXlaZVFAl>)(j4**N3U3{fo^&KPJOj<5q#a3wJyPWAV$VSvZwGT5g4fy2-)A6QL%fr
zD{tcI-35U*udPdAPi(kqTW{q)Mv-LAC)xg~Rfnp_UqttL<V~`#QIccYpJ2ZoU;FE8
z&8UHKyg_Czd(^l#^+U=M;HfC8jAG2TNy;EK&1*W8o2XAc-_u6h88<Ko_8l5K;<Vwn
zcSvp}HLha%{aYDfgC^PKNc(|H9h{<WS6bgkTJC#)r4^PrQm?ADhg0D>LyoMjf#d~^
zhjWUycP6;c<Csa=H_R^~8BUhXCKq4@$wp$V3V(U2AQIL7Yz)@;BTFoi*QXb$&>Bm3
zvA}V43LBc{Cn(K1IVo;Rh<uG~9}KnL_F1S+j@vMDT39ToJ-ux7*#>q(eBO-%$Ky)o
zs1(^i%?&*v?~j4q3l|$CP*8E8w<#;E%PJ>-R~zEi#%x4imh|S{AyLlFEX3t5sZ$y<
zr2&PS&rCNp8|kvPRX#zZmO`(~+1&YyPl-6R<v;1BVfoN*I@@buRQrM<F}}vlh(N6`
ze+}J=T8=~+vV&#Akly2yw$J=A51YQ?;dq$a7uR+Zayh|fU2`tDosTz|_}ILNPZQGT
z8PNz=%G6!!K{Fe_i@SAR*vWHmn=?b^M)QnJeI{*pM{lB?k^A_<3`+}_%*DyULm^_u
z?V{=GA@xC|yn@7q33co@`4<^y2b(VuG@f`JvioB9rtU!KADIrhZYDb4v%M9m&WCsS
zdR-+H3})bmh69X!TMAM?hGfu>#kZscV#1%tQ<+ljo9j>@$l|LUsC5sp2B51$k_B*2
z;s1vhD%6sx$jVlYFY<h>jJ-7;22fVwZUYE^_2WMcapbqUM7mu^Bk(M#&bdk1d^|3!
zfj0&134>ax3~m0%ZJaJms&3Jq%nc=6V&U{kqz`vu^-3sP>QI<EUKZG=U|Pk#S6+zF
zvDh3&(Mlg32Y0}oMYs$L*0sI^<T!t287&!y@_nuE-o0M4cz8rw9_N;LlBe1jF<EsW
z;(9Mj`Xgl9mm^(HFpc+=)neAD;aPm|)Ph>`2G<IIbdVIC&}l9&ko%zXnBj6%2NO0t
z8#u8ynJU1=P@X&826**4n#cvIXv0ODx-k91<Zn+@jTZ@8mIj#-*3pT6pDH1D3#J~w
zWCrye4t~Kq*8(O5-$F&M94P5~(^j6U$=2upyZ^dNK(fK+TVae1u<z(ABxUomi1CC&
zy^_l1@87?%3)ly`?E92{<pq@d*Imp9dg>RSy7le)31UT8v`)QrK_9V8bpQ=mj*3?$
z1>Zs4s3?pngKE#Ue`A~HbxbOA6u9OZnO<_|Xphs;2gefII7HzX*P*X_%wKQt;_)}D
zn2Yw-^3yG4FWL3m*16?7s0heFEv&x_=C;K5TQx0jE+VEkE+qVJhphTz#A3A9@J%(n
z$0C>2*H;xxN5#4@PQta>`Z*oOn}YP`R5xlU<GdJ@<$Z|C-r`y-V|U&^5@6z?;y*#T
z)xGE??bo^?^LmY74AWLp^a%45y3A_`CAu);E9b0Y`lSgdviyx0mno&u9BLa1H)PN&
z1ZC_gC;@y<qSqRG_h7z+tPA^)IAbV-8TT%3@x{b6&4TWW?d^I~=sk^IdILWd9q@KQ
zkl)wW<N8C2-e`4{+1L1n*$`$R@$9{CW`6JizE7PRgE35&O!w?E>v`V;DhtEc>NP2n
zWZ6X{2i}&*-d)67Q3;l7=R3E>9wwp1hHU=1Qf$1_)KKa7rhSOnk^AD-&-GWD-D3;d
zc}3g1<!3?;9~4OfvfUFZ3Y=MV?Q;Y7+YxBxoC5pbN96zk0A+<T3AdEN|1h>>DZcML
Vmg2ytfBjeh#2HsO+u`#4zX6bUnzjG{

literal 0
HcmV?d00001

diff --git a/tests/test_steganalysis.py b/tests/test_steganalysis.py
index 26ae607..61dac1c 100644
--- a/tests/test_steganalysis.py
+++ b/tests/test_steganalysis.py
@@ -50,6 +50,15 @@ class TestSteganalysis(unittest.TestCase):
         diff = ImageChops.difference(target, analysis).getbbox()
         self.assertTrue(diff is None)
 
+    def test_parity_rgba(self):
+        """ Test that stegano.steganalysis.parity works with RGBA images
+        """
+        img = Image.open('./tests/sample-files/transparent.png')
+        analysis = parity.steganalyse(img)
+        target = Image.open("./tests/expected-results/parity_rgba.png")
+        diff = ImageChops.difference(target, analysis).getbbox()
+        self.assertTrue(diff is None)
+
 
 if __name__ == '__main__':
     unittest.main()