【悬赏10V】双线性插值求优化【更新2.1 @2011-11-28】 - Project1

#==============================================================================
# ■ 双线性插值 2.1 by 各种压力的猫君
#------------------------------------------------------------------------------
# 　双线性插值图像缩放算法
# 仅供测试，当Bitmap尺寸较大时效率很差暂时不具实用性。
#------------------------------------------------------------------------------
# 使用方法：
# Bilinear.new(bitmap, x_rate, y_rate, type)
# bitmap ：原Bitmap
# x_rate ：横轴放大率
# y_rate ：纵轴放大率
# type ：缩放参数（1:加权平均 2:算术平均）
#
# 缩放后的Bitmap会被输出到全局变量$new_bitmap。
# 缩放结束后可以在全局变量$bilinear_time获取处理全程花费的时间（秒）
#------------------------------------------------------------------------------
# 更新记录：
# 2.1 2011-11-28 优化效率
# 2.0 2011-11-25 测试版（别问我1.0哪去了）
#==============================================================================
class Bilinear
#--------------------------------------------------------------------------
# ● 初始化对像
#--------------------------------------------------------------------------
def initialize(bitmap, x_rate, y_rate, type = 1)
# 获取原Bitmap及宽高信息
@old_bitmap = bitmap
@old_width = @old_bitmap.width
@old_height = @old_bitmap.height
# 生成一个储存所有像素颜色的数组
@color_array = []
# 每行从左到右的顺序依次获取颜色并压入数组
for line in 1..@old_height
for row in 1..@old_width
color = @old_bitmap.get_pixel(row, line)
@color_array.push color
end
end
# 获取放大率
@x_rate = x_rate
@y_rate = y_rate
# 根据放大率计算新Bitmap尺寸
@new_width = @x_rate * @old_width
@new_height = @y_rate * @old_height
# 生成Bitmap
@new_bitmap = Bitmap.new(@new_width, @new_height)
# 绘制Bitmap
draw(type)
# 返回Bitmap
$new_bitmap = @new_bitmap.clone
# 消除临时Bitmap
@new_bitmap.dispose
end
#--------------------------------------------------------------------------
# ● 绘制Bitmap
#--------------------------------------------------------------------------
def draw(type)
# 记录目前时间，用于统计算法用时
@time_begin = Time.now
# 一行一行绘制
for line in 1..@new_height
# 过程1：获取本行通用浮点y坐标
do_math_1(line)
for row in 1..@new_width
# 过程2：获取浮点x坐标
do_math_2(row)
# 过程3：获取颜色
do_math_3
# 过程4：计算颜色
do_math_4(type)
# 绘制颜色
draw_color(row, line)
end
end
# 计算算法用时
$bilinear_time = Time.now - @time_begin
end
#--------------------------------------------------------------------------
# ● 计算（过程1：获取浮点y坐标及y权）
#--------------------------------------------------------------------------
def do_math_1(y)
# 获取新坐标对应在原图上的浮点坐标
@y = 100 * y / @y_rate
# 计算y权
@ya = @y % 100
@yb = 100 - @ya
# 获取底数（floor）
@yf = @y /= 100
end
#--------------------------------------------------------------------------
# ● 计算（过程2：获取浮点x坐标及x权）
#--------------------------------------------------------------------------
def do_math_2(x)
# 获取新坐标对应在原图上的浮点坐标
@x = 100 * x / @x_rate
# 计算x权
@xa = @x % 100
@xb = 100 - @xa
# 获取底数（floor）
@xf = @x /= 100
end
#--------------------------------------------------------------------------
# ● 计算（过程3：获取颜色）
#--------------------------------------------------------------------------
def do_math_3
# 计算坐标颜色储存在数组中的序列
index11 = @xf + (@yf - 1) * @old_width - 1
if @ya == 0
index21 = index11
else
index21 = index11 + @old_width
end
if @xa == 0
index12 = index11
index22 = index21
else
index12 = index11 + 1
index22 = index21 + 1
end
# 从数组中获取颜色
@color11 = @color_array[index11]
@color21 = @color_array[index21]
@color12 = @color_array[index12]
@color22 = @color_array[index22]
end
#--------------------------------------------------------------------------
# ● 计算（过程4：计算颜色）
#--------------------------------------------------------------------------
def do_math_4(type)
# 分解颜色
@c11 = decompose_color(@color11)
@c21 = decompose_color(@color21)
@c12 = decompose_color(@color12)
@c22 = decompose_color(@color22)
if type == 1
# 加权
@c11 = weighted_average(@c11, @xa)
@c21 = weighted_average(@c21, @xa)
@c12 = weighted_average(@c12, @xb)
@c22 = weighted_average(@c22, @xb)
# 计算新颜色
@r = ((@c11[0] + @c12[0]) * @ya + (@c21[0] + @c22[0]) * @yb) / 10000
@g = ((@c11[1] + @c12[1]) * @ya + (@c21[1] + @c22[1]) * @yb) / 10000
@b = ((@c11[2] + @c12[2]) * @ya + (@c21[2] + @c22[2]) * @yb) / 10000
@a = ((@c11[3] + @c12[3]) * @ya + (@c21[3] + @c22[3]) * @yb) / 10000
elsif type == 2
# 计算新颜色
@r = (@c11[0] + @c12[0] + @c21[0] + @c22[0]) / 4
@g = (@c11[1] + @c12[1] + @c21[1] + @c22[1]) / 4
@b = (@c11[2] + @c12[2] + @c21[2] + @c22[2]) / 4
@a = (@c11[3] + @c12[3] + @c21[3] + @c22[3]) / 4
end
end
#--------------------------------------------------------------------------
# ○ 分解颜色
#--------------------------------------------------------------------------
def decompose_color(color)
r = color.red
g = color.green
b = color.blue
a = color.alpha
color_array = [r, g, b, a]
return color_array
end
#--------------------------------------------------------------------------
# ○ 加权运算
#--------------------------------------------------------------------------
def weighted_average(array, d)
new_array = []
array.each do |i|
new_array.push i * d
end
return new_array
end
#--------------------------------------------------------------------------
# ● 绘制颜色
#--------------------------------------------------------------------------
def draw_color(x, y)
color = Color.new(@r, @g, @b, @a)
@new_bitmap.set_pixel(x, y, color)
end
end

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class Bilinear < Bitmap #bitmap爸爸的意思
def initialize(bitmap, x_rate, y_rate)
old_width = bitmap.width
old_height = bitmap.height
width = (old_width * x_rate).round
height = (old_height * y_rate).round
new_width = width + x_rate.ceil #计算时多放大1些
new_height = height + y_rate.ceil #使四边上的颜色最接近原图四边
array = []
for y in 0...old_height
for x in 0...old_width
array.push(bitmap.get_pixel(x, y))
end
end
bitmap.dispose
color = Color.new(0, 0, 0, 0) #新生成比.set多用 6% 秒
super(width, height) #生成Bitmap对象
for y in 0...height
t = y * old_height ; ty = t / new_height #省计算临时变量
ty1 = ty * old_width ; ty2 = ty1 + old_width #取得数组中y位
y2 = t % new_height * 100 / new_height #计算百分比位置
y1 = 100-y2
for x in 0...width
t = x * old_width; tx = t / new_width #省计算临时变量; 取得数组中x位
x2 = t % new_width * 100 / new_width #计算百分比位置
x1 = 100-x2
# 取得四点百分比; 取得四点颜色
b11 = x1*y1; c11 = array[ty1 + tx]
b21 = x2*y1; c21 = array[ty1 + tx+1]
b12 = x1*y2; c12 = array[ty2 + tx]
b22 = x2*y2; c22 = array[ty2 + tx+1]
# 根据四点百分比来调整颜色
red = (c11.red*b11 + c21.red*b21 + c12.red*b12 + c22.red*b22) / 10000
green = (c11.green*b11 + c21.green*b21 + c12.green*b12 + c22.green*b22) / 10000
blue = (c11.blue*b11 + c21.blue*b21 + c12.blue*b12 + c22.blue*b22) / 10000
alpha = (c11.alpha*b11 + c21.alpha*b21 + c12.alpha*b12 + c22.alpha*b22) / 10000
set_pixel(x, y, color.set(red, green, blue, alpha))
end
end
end
end
time = Time.new
@a = Sprite.new
@a.bitmap = Bilinear.new(Bitmap.new("TEST.png"),0.6,0.6)
p Time.new - time

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