QuachFu - Revision history

imported>Projects221: /* 2D FFT */

2013-03-20T02:52:28Z

2D FFT

← Older revision		Revision as of 02:52, 20 March 2013
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	=== 2D FFT ===		=== 2D FFT ===

	If we take the two dimensional FFT of the probability map and plot it, then we can more clearly see the periodic patterns which manifests itself as peaks in the graph. In the figure below, the probability map is up-sampled by a factor of two in order to push the peaks towards the center for visibility reasons. The resulting FFT data is also shifted to move the zero peak to the center, as well as having the log() function and gamma correction applied to it to make the peaks more distinct. The peaks in the center of each quadrant represent the periodic pattern of the interpolated pixels.		If we take the two dimensional FFT of the probability map and plot it, then we can more clearly see the periodic patterns which manifests itself as peaks in the graph. In the figure below, the probability map is up-sampled by a factor of two in order to push the peaks towards the center for visibility reasons. The resulting FFT data is also shifted to move the zero peak to the center, as well as having the log() function and gamma correction applied to it to make the peaks more distinct. The peaks in the center of each quadrant represent the periodic pattern of the interpolated pixels. Figure 3 shows the 2D FFT of an image with CFA interpolation and Figure 4 shows one without CFA interpolation.

	[[File:2DFFT.png \|thumb\|center\|500px\|Figure 3: 2D FFT of Probability Map for Original Image]] [[File:2DFFT_fake.png \|thumb\|center\|500px\|Figure 4: 2D FFT of Probability Map for Tampered Image]]		[[File:2DFFT.png \|thumb\|center\|500px\|Figure 3: 2D FFT of Probability Map for Original Image]] [[File:2DFFT_fake.png \|thumb\|center\|500px\|Figure 4: 2D FFT of Probability Map for Tampered Image]]


	=== Similarity Measure ===		=== Similarity Measure ===

imported>Projects221: /* Uncompressed Images */

2013-03-20T02:50:15Z

Uncompressed Images

← Older revision		Revision as of 02:50, 20 March 2013
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	== Uncompressed Images ==		== Uncompressed Images ==

			Figure 5 is the similarity measures for each channel for each window of the original image. The similarity measures in Figure 5 are quite a bit higher than the ones in Figure 6, which are the similarity measures the corresponding altered image.

	[[File:RealPlot.png \|thumb\|center\|500px\|Figure 5: Normalized Similarity Measure for Original Image]] [[File:FakePlot.png\|thumb\|center\|500px\|Figure 6: Normalized Similarity Measure for Tampered Image]]		[[File:RealPlot.png \|thumb\|center\|500px\|Figure 5: Normalized Similarity Measure for Original Image]] [[File:FakePlot.png\|thumb\|center\|500px\|Figure 6: Normalized Similarity Measure for Tampered Image]]

imported>Projects221: /* Test Images */

2013-03-19T23:44:52Z

Test Images

← Older revision		Revision as of 23:44, 19 March 2013
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	Resized066.real.png true picture		Resized066.real.png true picture

	False Positive Rate = 10%		False Positive Rate = 10%, Sensitivity = 20%

	= Conclusions =		= Conclusions =

imported>Projects221: /* Test Images */

2013-03-19T23:41:48Z

Test Images

← Older revision		Revision as of 23:41, 19 March 2013
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	Resized066.real.png true picture		Resized066.real.png true picture

			False Positive Rate = 10%

	= Conclusions =		= Conclusions =

imported>Projects221 at 23:34, 19 March 2013

2013-03-19T23:34:28Z

← Older revision		Revision as of 23:34, 19 March 2013
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	== Test Images ==		== Test Images ==

			tp3f84b1d8_60eb_4254_9dbe_657421e27500.fake.png true picture

			tp3f84b1d8_60eb_4254_9dbe_657421e27500.real.png true picture

			tp501a096a_72e7_4c96_989f_3bedf5b928db.fake.png true picture

			tp501a096a_72e7_4c96_989f_3bedf5b928db.real.png true picture

			tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.fake.png true picture

			tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.real.png true picture

			tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.fake.png true picture

			tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.real.png true picture

			tpcb9fdff3_ca6d_4786_8763_2014a920d19e.fake.png true picture

			tpcb9fdff3_ca6d_4786_8763_2014a920d19e.real.png true picture

			tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.fake.png FALSE PICTURE

			tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.real.png true picture

			JPEGQ100fake.png true picture

			JPEGQ100real.png true picture

			JPEGQ30fake.png true picture

			JPEGQ30real.png true picture

			JPEGQ60fake.png FALSE PICTURE

			JPEGQ60real.png FALSE PICTURE

			Resized066.fake.png true picture

			Resized066.real.png true picture

	= Conclusions =		= Conclusions =

imported>Projects221: /* Test Images */

2013-03-19T23:32:08Z

Test Images

← Older revision		Revision as of 23:32, 19 March 2013
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	== Test Images ==		== Test Images ==

	~~tp3f84b1d8_60eb_4254_9dbe_657421e27500.fake.png true picture~~

	~~tp3f84b1d8_60eb_4254_9dbe_657421e27500.real.png true picture~~

	~~tp501a096a_72e7_4c96_989f_3bedf5b928db.fake.png true picture~~

	~~tp501a096a_72e7_4c96_989f_3bedf5b928db.real.png true picture~~

	~~tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.fake.png true picture~~

	~~tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.real.png true picture~~

	~~tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.fake.png true picture~~

	~~tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.real.png true picture~~

	~~tpcb9fdff3_ca6d_4786_8763_2014a920d19e.fake.png true picture~~

	~~tpcb9fdff3_ca6d_4786_8763_2014a920d19e.real.png true picture~~

	~~tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.fake.png FALSE PICTURE~~

	~~tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.real.png true picture~~

	~~JPEGQ100fake.png true picture~~

	~~JPEGQ100real.png true picture~~

	~~JPEGQ30fake.png true picture~~

	~~JPEGQ30real.png true picture~~

	~~JPEGQ60fake.png FALSE PICTURE~~

	~~JPEGQ60real.png FALSE PICTURE~~

	~~Resized066.fake.png true picture~~

	~~Resized066.real.png true picture~~

	= Conclusions =		= Conclusions =

imported>Projects221: /* Test Images */

2013-03-19T23:31:33Z

Test Images

← Older revision		Revision as of 23:31, 19 March 2013
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	tp3f84b1d8_60eb_4254_9dbe_657421e27500.fake.png true picture		tp3f84b1d8_60eb_4254_9dbe_657421e27500.fake.png true picture

	tp3f84b1d8_60eb_4254_9dbe_657421e27500.real.png true picture		tp3f84b1d8_60eb_4254_9dbe_657421e27500.real.png true picture

	tp501a096a_72e7_4c96_989f_3bedf5b928db.fake.png true picture		tp501a096a_72e7_4c96_989f_3bedf5b928db.fake.png true picture

	tp501a096a_72e7_4c96_989f_3bedf5b928db.real.png true picture		tp501a096a_72e7_4c96_989f_3bedf5b928db.real.png true picture

	tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.fake.png true picture		tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.fake.png true picture

	tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.real.png true picture		tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.real.png true picture

	tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.fake.png true picture		tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.fake.png true picture

	tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.real.png true picture		tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.real.png true picture

	tpcb9fdff3_ca6d_4786_8763_2014a920d19e.fake.png true picture		tpcb9fdff3_ca6d_4786_8763_2014a920d19e.fake.png true picture

	tpcb9fdff3_ca6d_4786_8763_2014a920d19e.real.png true picture		tpcb9fdff3_ca6d_4786_8763_2014a920d19e.real.png true picture

	tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.fake.png FALSE PICTURE		tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.fake.png FALSE PICTURE

	tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.real.png true picture		tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.real.png true picture
	~~=(((~~
			JPEGQ100fake.png true picture

			JPEGQ100real.png true picture

			JPEGQ30fake.png true picture

			JPEGQ30real.png true picture

			JPEGQ60fake.png FALSE PICTURE

			JPEGQ60real.png FALSE PICTURE

			Resized066.fake.png true picture

			Resized066.real.png true picture

	= Conclusions =		= Conclusions =

imported>Projects221 at 23:30, 19 March 2013

2013-03-19T23:30:47Z

← Older revision		Revision as of 23:30, 19 March 2013
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	As seen in this 2D FFT plot, jpeg images did not show any periodic interpolation as there are no visible peaks in Figure 7. This would correlate to a low similarity measure score and thus our classifier would classify all jpeg images as fake.		As seen in this 2D FFT plot, jpeg images did not show any periodic interpolation as there are no visible peaks in Figure 7. This would correlate to a low similarity measure score and thus our classifier would classify all jpeg images as fake.

			== Test Images ==

			tp3f84b1d8_60eb_4254_9dbe_657421e27500.fake.png true picture
			tp3f84b1d8_60eb_4254_9dbe_657421e27500.real.png true picture
			tp501a096a_72e7_4c96_989f_3bedf5b928db.fake.png true picture
			tp501a096a_72e7_4c96_989f_3bedf5b928db.real.png true picture
			tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.fake.png true picture
			tp8ba7ba67_d78a_4b01_bd41_c6440a7c69c6.real.png true picture
			tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.fake.png true picture
			tpc69b985f_2cd4_4fd8_89ef_08acae1f754c.real.png true picture
			tpcb9fdff3_ca6d_4786_8763_2014a920d19e.fake.png true picture
			tpcb9fdff3_ca6d_4786_8763_2014a920d19e.real.png true picture
			tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.fake.png FALSE PICTURE
			tpd4e65e8d_7310_43ab_98f8_a9e1d9a7e40f.real.png true picture
			=(((

	= Conclusions =		= Conclusions =

imported>Projects221: /* JPEG Images */

2013-03-19T23:27:37Z

JPEG Images

← Older revision		Revision as of 23:27, 19 March 2013
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	== JPEG Images ==		== JPEG Images ==

	On our test set of jpg images, our classifier could not handle ~~jpg~~ compression and classified all images as fake images regardless of Q factor.		On our test set of jpg images, our classifier could not handle jpeg compression and classified all images as fake images regardless of Q factor.

	[[File:jpeg.png \|thumb\|500px\|center\|Figure 7: 2D FFT of Probability Map of JPEG image with Q-factor = 70]]		[[File:jpeg.png \|thumb\|500px\|center\|Figure 7: 2D FFT of Probability Map of JPEG image with Q-factor = 70]]

			As seen in this 2D FFT plot, jpeg images did not show any periodic interpolation as there are no visible peaks in Figure 7. This would correlate to a low similarity measure score and thus our classifier would classify all jpeg images as fake.

	= Conclusions =		= Conclusions =

imported>Projects221: /* JPEG Images */

2013-03-19T23:25:37Z

JPEG Images

← Older revision		Revision as of 23:25, 19 March 2013
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	== JPEG Images ==		== JPEG Images ==

	On our test set of jpg images, our classifier could not handle jpg compression and classified all images as fake images regardless of Q factor. :(		On our test set of jpg images, our classifier could not handle jpg compression and classified all images as fake images regardless of Q factor.

	[[File:jpeg.png \|thumb\|500px\|center\|Figure 7: 2D FFT of Probability Map of JPEG image with Q-factor = 70]]		[[File:jpeg.png \|thumb\|500px\|center\|Figure 7: 2D FFT of Probability Map of JPEG image with Q-factor = 70]]


	= Conclusions =		= Conclusions =