# MaskHS

From Avisynth wiki

Returns a mask (as Y8) of clip using a given hue and saturation range. Added in v2.6.

AVS+ adds new realcalc parameter.

## Syntax and Parameters

MaskHS(clip [, int *startHue*, int *endHue*, int *maxSat*, int *minSat*, bool *coring* ] )

MaskHS(clip [, int *startHue*, int *endHue*, int *maxSat*, int *minSat*, bool *coring*,
bool *realcalc* ] ) AVS+

*int*startHue =*0*

*int*endHue =*360*

- The resulting mask will contain source values in the range [startHue, endHue] when startHue<endHue. Note that the hue is periodic, thus a hue of 360 degrees corresponds with a hue of zero degrees.

- If endHue<startHue then the range [endHue, 360] and [0, startHue] will be selected (thus anti-clockwise). If you need to select a range of [350, 370] for example, you need to specify startHue=370, endHue=350.

- Range 0 to 360 (degrees), default 0, 360; thus when using the default values, all pixels will be processed.

- The following shows some arbitrary startHue and endHue values for the basic colors, with a Histogram vectorscope to illustrate the color circle:

**Color****startHue**(center) **endHue**Red 075 102 115 Yellow 150 176 180 Green 191 230 258 Cyan 279 282 300 Blue 316 000 004 Magenta 028 048 052

*int*maxSat =*150*

*int*minSat =*0*

- The resulting mask will contain source values in the range [minSat, maxSat].

- Practically the saturation of a pixel will be in the range [0,100] (thus 0-100%), since these correspond to valid RGB pixels (100% corresponds to R=255, G=B=0, which has a saturation of 119). An overshoot (up to 150%) is allowed for non-valid RGB pixels (150% corresponds to U=V=255, which has a saturation of sqrt(127
^{2}+127^{2}) = 180). - AVS+ TODO needs documentation of behavior with Deep Color formats.

- Practically the saturation of a pixel will be in the range [0,100] (thus 0-100%), since these correspond to valid RGB pixels (100% corresponds to R=255, G=B=0, which has a saturation of 119). An overshoot (up to 150%) is allowed for non-valid RGB pixels (150% corresponds to U=V=255, which has a saturation of sqrt(127

- Range 0 to 150 (percent), default 150, 0; thus when using the default values all pixels will be processed.

*bool*coring =*true*

- When set to true, the luma (Y) is clipped to TV-range; when set to false, the luma is left untouched.

*bool*realcalc =*false*

- AVS+ When true, force 'no-lookup': pure float calculation of new pixel values (always true for certain Deep Color formats) (TODO - clarify)

## Examples

- Suppose we want to create a mask of the skin of the girl below. The proper way to do this is to look at the vectorscope of Histogram:

- and estimate the hue range you want to select. As can be seen, the orange hue is between (about) 105 and 165 degrees.
*Note: axis labels have been added to the vectorscope as a guide – they are not generated by the above script*

- Start with a wide hue range and narrow it until the output of
**MaskHS**isolates the range of interest. You can also use Tweak to preview the affected range (with*sat*=0), as the arguments are compatible.

- In our example we end at startHue=105, endHue=138, and the following mask is obtained:

- Looking at the blue screen example in Overlay the following can be used

testcard = ColorBars # example subtitle file with blue background: subs = ImageSource("F:\TestClips\blue.jpg").ConvertToYV24 # subs.Histogram(mode="color2").ConvertToRGB # blue in [345,359] mask_hs = subs.MaskHS(startHue=340, endHue=359).Levels(0, 1, 255, 255, 0) Overlay(testcard, subs, mask=mask_hs, mode="blend", opacity=1)

## Changelog

v2.60 | Initial Release |