JaroensriTanDejesus - Revision history

imported>Psych2012: /* Skin Morphing Results */

2012-03-20T21:10:27Z

Skin Morphing Results

← Older revision		Revision as of 21:10, 20 March 2012
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	Asian skin color (green line), morphed skin color (blue line)]]		Asian skin color (green line), morphed skin color (blue line)]]
	\|}		\|}
	Figure 2a shows the transformation of a dark skin color into a light skin color. Visually, we can ~~see~~ the ~~match in~~ skin color is ~~more accurate compared~~ to ~~the previous sample~~. In our comparison plot of reflectance values, the spectral reflectance of the morphed image is very similar to the spectral reflectance of the the target light skin (Figure 2b). Specular reflectance can be observed at the forehead and bottom of the nose which makes the morphed image look unrealistic.		Figure 2a shows the transformation of a dark skin color into a light skin color. Visually, we can the skin color is close to asian colored skin, but it comes out lighter. However in our comparison plot of reflectance values, the spectral reflectance of the morphed image is very similar to the spectral reflectance of the the target light skin (Figure 2b). We suspect that reflectance variance is boosted when morphing dark skin into light skin. Specular reflectance can be observed at the forehead and bottom of the nose which makes the morphed image look unrealistic.

	{\|		{\|

imported>Psych2012: /* Result */

2012-03-20T21:07:50Z

Result

← Older revision		Revision as of 21:07, 20 March 2012
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	=== Result ===		=== Result ===

	In RGB space, we seem to get independent channels that were uniformly recognizable across different people., especially the hemoglobin channel always seemed to be distinct, and shading-free. However, morphing different people by substituting their channel ~~profile~~, i.e. separation matrix/mixing matrix (see [1]), does not seem to work well. The channel that seemed to be melanin do not truly represent the melanin color, because the “shading” component was not completely black-white, so it also played a role in rendering the correct skin color.		In RGB space, we seem to get independent channels that were uniformly recognizable across different people, especially the hemoglobin channel always seemed to be distinct and shading-free. However, morphing different people by substituting their channel profiles, i.e. separation matrix/mixing matrix (see [1]), does not seem to work well. The channel that seemed to be melanin do not truly represent the melanin color, because the “shading” component was not completely black-white, so it also played a role in rendering the correct skin color.

	We tried selecting different channels for morphing. We also tried adjusting and matching the channel strength. These techniques worked in some cases (see image below), but it fails most of the time, especially when we tried to morph hemoglobin channel. The morphed image always turned green due to imbalance of red/yellow in the skin.		We tried selecting different channels for morphing. We also tried adjusting and matching the channel strength. These techniques worked in some cases (see image below), but it fails most of the time, especially when we tried to morph hemoglobin channel. The morphed image always turned green due to imbalance of red/yellow in the skin.
	In many cases, the extracted melanin profiles for both dark skin and light skin were quite similar, so when we morph the melanin channel, almost no effect is seen. On the contrary, some similar skins have different profile, so when we morph between the two, an unrealistic effect was created (morphing white skin to yellow skin, but the result becomes a dark skin~~, Figure...~~)		In many cases, the extracted melanin profiles for both dark skin and light skin were quite similar, so when we morph the melanin channel, almost no effect is seen. On the contrary, some similar skins have different profile, so when we morph between the two, an unrealistic effect was created (morphing white skin to yellow skin, but the result becomes a dark skin)
	[[File:BtoA.png\|thumb\|1000px\|left\|Morphing of light skin (middle) to dark skin (left). The result is shown on right. Note that the skin was darkened, but the color still don't match]]		[[File:BtoA.png\|thumb\|1000px\|left\|Morphing of light skin (middle) to dark skin (left). The result is shown on right. Note that the skin was darkened, but the color still don't match]]

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	[[File:AtoIadjusted.png\|thumb\|1000px\|left\|Morphing of middle to left. The result is shown on right. Same morph as above right, but with adjusted signal power. Note that the skin tone looked more similar, but still noticeably different]]		[[File:AtoIadjusted.png\|thumb\|1000px\|left\|Morphing of middle to left. The result is shown on right. Same morph as above right, but with adjusted signal power. Note that the skin tone looked more similar, but still noticeably different]]

			[[File:Green.png\|thumb\|1000px\|left\|Morphing of middle to left. The result is shown on right. Morphing hemoglobin often result in green-ing image, the cause seems to be the subtle different in the green channel of hemoglobin color for each person ]]

	== Reflectance Domain ==		== Reflectance Domain ==

imported>Psych2012: /* Skin Morphing Results */

2012-03-20T21:06:04Z

Skin Morphing Results

← Older revision		Revision as of 21:06, 20 March 2012
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	{\|		{\|
	\|[[File:Joyce_African.jpg\|600px\|thumb\|left\|Figure 3a: Transformation of Joyce skin color into African American skin color]]		\|[[File:Joyce_African.jpg\|600px\|thumb\|left\|Figure 3a: Transformation of Joyce skin color into African American skin color]]
	\|[[File:JoyceR.JPG\|400px\|thumb\|right\|Figure 3b: Spectral reflectance of ~~Caucasian~~ skin color (red line), African American skin color (green line), morphed skin color (blue line)]]		\|[[File:JoyceR.JPG\|400px\|thumb\|right\|Figure 3b: Spectral reflectance of Joyce's skin color (red line), African American skin color (green line), morphed skin color (blue line)]]
	\|}		\|}
	Figure 3a shows the transformation of a light skin color into a dark skin color. The morphed skin color is not an accurate match to the target skin color. We believe this is caused by incorrect estimates of the spectral reflectances in Joyce’s scene. Joyce’s light skin color spectral reflectance has lower values compared to other light skin samples we tested on, hence making our computation results inaccurate. Specular reflectance can be observed at the forehead, edges of the face, and nose which causes regions to not be transformed.		Figure 3a shows the transformation of a light skin color into a dark skin color. The morphed skin color is not an accurate match to the target skin color. We believe this is caused by incorrect estimates of the spectral reflectances in Joyce’s scene. Joyce’s light skin color spectral reflectance has lower values compared to other light skin samples we tested on, hence making our computation results inaccurate. Specular reflectance can be observed at the forehead, edges of the face, and nose which causes regions to not be transformed.

imported>Psych2012: /* Skin Morphing Results */

2012-03-20T21:04:09Z

Skin Morphing Results

← Older revision		Revision as of 21:04, 20 March 2012
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	==== Skin Morphing Results ====		==== Skin Morphing Results ====
	{\|		{\|
	\|[[File:Caucasian-American.JPG\|600px\|left\|thumb\|Figure 1a: Transformation of Caucasian skin color into African American skin color]] \|\|[[File:~~LightDarkReflectance~~.JPG\|420px\|right\|thumb\|Figure 1b: Spectral reflectance of Caucasian skin color (red line), African American skin color (green line), morphed skin color (blue line)]]		\|[[File:Caucasian-American.JPG\|600px\|left\|thumb\|Figure 1a: Transformation of Caucasian skin color into African American skin color]] \|\|[[File:CaucasianR.JPG\|420px\|right\|thumb\|Figure 1b: Spectral reflectance of Caucasian skin color (red line), African American skin color (green line), morphed skin color (blue line)]]
	\|}		\|}
	Figure 1a shows the transformation of a light skin color to a dark skin color. In the RGB space, the morphed skin color looks close to the target dark skin color. We chose to plot the reflectance values at the center of a person’s right cheek to compare the spectral reflectances between the source person, the target person, and the morphed person. In the reflectance space,the spectral reflectance of the morphed skin sample does not matches the shape of the target (person 2) reflectance exactly, but it follows the general trend (Figure 1b). Shading seems to be preserved in the transformation.		Figure 1a shows the transformation of a light skin color to a dark skin color. In the RGB space, the morphed skin color looks close to the target dark skin color. We chose to plot the reflectance values at the center of a person’s right cheek to compare the spectral reflectances between the source person, the target person, and the morphed person. In the reflectance space,the spectral reflectance of the morphed skin sample does not matches the shape of the target (person 2) reflectance exactly, but it follows the general trend (Figure 1b). Shading seems to be preserved in the transformation.

imported>Psych2012: /* Our Method */

2012-03-20T21:02:46Z

Our Method

← Older revision		Revision as of 21:02, 20 March 2012
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	=== Our Method ===		=== Our Method ===

	We simplified Tsumura’s algorithm by performing ICA on the (RGB) image and separate them into three independent components. In reflectance space we would be able to extract more ~~channel~~. To reduce computation time and avoid including non-skin part of the image, we select the area around the cheek of the subject to find separation matrix, and use that to separate the whole image. The result in RGB seemed to reveal some underlying property of the skin, whereas the same analysis on hyperspectral data yielded many unrecognizable channels. (See image below) So, most of our work with this approach was mainly in RGB space.		We simplified Tsumura’s algorithm by performing ICA on the (RGB) image and separate them into three independent components. In reflectance space we would be able to extract more channels. To reduce computation time and avoid including non-skin part of the image into the analysis, we select the area around the cheek of the subject to find separation matrix, and use that to separate the whole image. The result in RGB seemed to reveal some underlying property of the skin, whereas the same analysis on hyperspectral data yielded many unrecognizable channels. (See image below) So, most of our work with this approach was mainly in RGB space.

imported>Psych2012: /* Skin Morphing Results */

2012-03-20T21:02:05Z

Skin Morphing Results

imported>Psych2012: /* Our Method */

2012-03-20T21:01:52Z

Our Method

← Older revision		Revision as of 21:01, 20 March 2012
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	=== Our Method ===		=== Our Method ===

	~~To make our analysis feasible, we~~ simplified Tsumura’s algorithm by performing ICA on the (RGB) image and separate them into three independent components. In reflectance space we would be able to extract more channel. To reduce computation time and avoid including non-skin part of the image, we select the area around the cheek of the subject to find separation matrix, and use that to separate the whole image. The result in RGB seemed to reveal some underlying property of the skin, whereas the same analysis on hyperspectral data yielded many unrecognizable channels. (See image below) So, most of our work with this approach was mainly in RGB space.		We simplified Tsumura’s algorithm by performing ICA on the (RGB) image and separate them into three independent components. In reflectance space we would be able to extract more channel. To reduce computation time and avoid including non-skin part of the image, we select the area around the cheek of the subject to find separation matrix, and use that to separate the whole image. The result in RGB seemed to reveal some underlying property of the skin, whereas the same analysis on hyperspectral data yielded many unrecognizable channels. (See image below) So, most of our work with this approach was mainly in RGB space.

imported>Psych2012: /* Theory and Previous Work */

2012-03-20T21:01:09Z

Theory and Previous Work

← Older revision		Revision as of 21:01, 20 March 2012
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	<math>C(x,y,\lambda) = e^{\sigma_m(\lambda)\rho_m(x,y)+\sigma_h(\lambda)\rho_h(x,y)}p(x,y)E(\lambda)-(1)</math>		<math>C(x,y,\lambda) = e^{\sigma_m(\lambda)\rho_m(x,y)+\sigma_h(\lambda)\rho_h(x,y)}p(x,y)E(\lambda)-(1)</math>

	, where c represents signal at wavelength <math>\lambda</math> on pixel (x,y), <math>\sigma_m,\rho_m,\sigma_h,\rho_h</math> represents absorbance and density of melanin and hemoglobin respectively, <math>p(x,y)</math> represents shading ~~function~~, and <math>E(\lambda)</math> represents illuminant at that wave length.		, where c represents signal at wavelength <math>\lambda</math> on pixel (x,y), <math>\sigma_m,\rho_m,\sigma_h,\rho_h</math> represents absorbance and density of melanin and hemoglobin respectively, <math>p(x,y)</math> represents shading strength, and <math>E(\lambda)</math> represents illuminant at that wave length.
	When we take a logarithm, all these dependencies become linear, and we could use independent component analysis to separate different absorbance channels, thus allowing us to decompose one’s facial image in a meaningful way [1].		When we take a logarithm, all these dependencies become linear, and we could use independent component analysis to separate different absorbance channels, thus allowing us to decompose one’s facial image in a meaningful way [1].

imported>Psych2012: /* Skin Morphing Results */

2012-03-20T20:59:23Z

Skin Morphing Results

← Older revision		Revision as of 20:59, 20 March 2012
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	{\|		{\|
	\|[[File:Joyce_African.jpg\|600px\|thumb\|left\|Figure ?: Transformation of Joyce skin color into African American skin color]]		\|[[File:Joyce_African.jpg\|600px\|thumb\|left\|Figure ?: Transformation of Joyce skin color into African American skin color]]
	\|[[File:~~Joyce_AfricanReflectance~~.~~jpg~~\|400px\|thumb\|right\|Figure ?: Spectral reflectance of Caucasian skin color (red line), African American skin color (green line), morphed skin color (blue line)]]		\|[[File:JoyceR.JPG\|400px\|thumb\|right\|Figure ?: Spectral reflectance of Caucasian skin color (red line), African American skin color (green line), morphed skin color (blue line)]]
	\|}		\|}
	Figure ? shows the transformation of a light skin color into a dark skin color. The morphed skin color is not an accurate match to the target skin color. We believe this is caused by incorrect estimates of the spectral reflectances in Joyce’s scene. Joyce’s light skin color spectral reflectance has lower values compared to other light skin samples we tested on, hence making our computation results inaccurate. Specular reflectance can be observed at the forehead, edges of the face, and nose which causes regions to not be transformed.		Figure ? shows the transformation of a light skin color into a dark skin color. The morphed skin color is not an accurate match to the target skin color. We believe this is caused by incorrect estimates of the spectral reflectances in Joyce’s scene. Joyce’s light skin color spectral reflectance has lower values compared to other light skin samples we tested on, hence making our computation results inaccurate. Specular reflectance can be observed at the forehead, edges of the face, and nose which causes regions to not be transformed.

imported>Psych2012: /* Result */

2012-03-20T20:58:09Z

Result

← Older revision		Revision as of 20:58, 20 March 2012
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	[[File:AtoI.png\|thumb\|1000px\|left\|Morphing of middle to left. The result is shown on right. Even though the original skins looked similar, the morphed was totally changed.]]		[[File:AtoI.png\|thumb\|1000px\|left\|Morphing of middle to left. The result is shown on right. Even though the original skins looked similar, the morphed was totally changed.]]

	[[File:AtoIadjusted.png\|thumb\|1000px\|~~center~~\|Morphing of middle to left. The result is shown on right. Same morph as above right, but with adjusted signal power. Note that the skin tone looked more similar, but still noticeably different]]		[[File:AtoIadjusted.png\|thumb\|1000px\|left\|Morphing of middle to left. The result is shown on right. Same morph as above right, but with adjusted signal power. Note that the skin tone looked more similar, but still noticeably different]]

	== Reflectance Domain ==		== Reflectance Domain ==