'应用反转变换': function () {
canvas.processRgb(function (r, g, b) {
return {
r: 255 - r,
g: 255 - g,
b: 255 - b
};
});
},
'应用RGB变换': function () {
canvas.processRgb(function (r, g, b) {
return {
r: r * param['R'],
g: g * param['G'],
b: b * param['B']
}
});
},
'应用对数变换': function () {
canvas.processRgb(function (r, g, b) {
var c = param['c'];
return {
r: c * Math.log(1 + r),
g: c * Math.log(1 + g),
b: c * Math.log(1 + b)
};
});
},
'应用伽马较正': function () {
canvas.processRgb(function (r, g, b) {
var c = param['c3'],
y = param['y2'];
return {
r: Math.pow(r / c, 1 / y) * c,
g: Math.pow(g / c, 1 / y) * c,
b: Math.pow(b / c, 1 / y) * c
};
});
}
'应用幂律变换': function () {
canvas.processRgb(function (r, g, b) {
var c = param['c2'],
y = param['y'];
return {
r: c * Math.pow(r, y),
g: c * Math.pow(g, y),
b: c * Math.pow(b, y)
};
});
},
'应用线性变换': function () {
canvas.processRgb(function (r, g, b) {
var yuv = util.rgbToYuv(r, g, b),
y = yuv.y,
grey = 0;
var a = param['a'],
b = param['b'],
c = param['c'],
d = param['d'];
if (y > b) {
grey = d;
} else if (y >= a && a <= b) {
grey = (d - c) / (b - a) * (y - a) + c;
} else {
grey = c;
}
return {
r: grey,
g: grey,
b: grey
};
});
}