本文主要向大家介绍了Photoshop入门学习之PS 滤镜算法原理——拼贴，通过具体的内容向大家展现，希望对大家Photoshop入门学习有所帮助。

%%%% Tile 
%%%%% 实现拼贴效果
%%%%% 将原图像进行分块，然后让图像块在
%%%%% 新图像范围内进行随机移动，确定移动后的边界
%%%%% 将移动后的图像块填入新图像内

clc;
clear all;
close all;

Image=imread('4.jpg');
Image1=double(Image);
Image2=Image1;

Image2(:,:,1)=0;
Image2(:,:,2)=0;
Image2(:,:,3)=0;

%%%% 块数 （1-99）
N=8; 
%%%% 错开距离的最大百分比（0.01-0.99）
Percent=0.25;
Size_Info=size(Image);

%%%  确定图像的长和宽
Height=Size_Info(1);
Width=Size_Info(2);

%%%  确定图像的分块大小，及错开的最大距离
Min_value=min(Width,Height);
Block_size=floor(Min_value/N);
Rand_Dist=max(Block_size*Percent,2);

%%% 确定图像在长和宽方向的块数
N_row=floor(Height/Block_size);
N_col=floor(Width/Block_size);
Block_height=0;
Block_width=0;

%%% 图像如果在长或宽方向有多余的，统计在内
if(N_row*Block_size<Height)
    Block_height=(Height-Block_size*N_row)/2;
    N_row=N_row+1;
end
if(N_col*Block_size<Width)
    Block_width=(Width-Block_size*N_col)/2;
    N_col=N_col+1;
end

First_value=(Block_size+1)/2;

%%% 图像块原始坐标
Row_coordinate_origin(1:N_row)=0;
Col_coordinate_origin(1:N_col)=0;
for i=1:N_row-1;
    Row_coordinate_origin(i)=round(First_value+(i-1)*Block_size);
end
Row_coordinate_origin(N_row)=round((Height+(N_row-1)*Block_size)/2);

for i=1:N_col-1
    Col_coordinate_origin(i)=round(First_value+(i-1)*Block_size);
end
Col_coordinate_origin(N_col)=round((Width+(N_col-1)*Block_size)/2);

%%% 图像块的错开后的坐标
Row_coordinate(1:N_row,1:N_col)=0;
Col_coordinate(1:N_row,1:N_col)=0;
for i=1:N_row;
    for j=1:N_col
    Row_coordinate(i,j)=Row_coordinate_origin(i)+floor(Rand_Dist*2*(rand()-0.5));
    end
end
for i=1:N_row
    for j=1:N_col
     Col_coordinate(i,j)=Col_coordinate_origin(j)+floor(Rand_Dist*2*(rand()-0.5));
    end
end

%%% 对图像进行拼贴处理
Block_half=(Block_size-1)/2;
for i=1:N_row
    for j=1:N_col
        %%% 首先确定错开后的坐标没有越界
        if(Row_coordinate(i,j)>Height || Col_coordinate(i,j)>Width)
            continue;
        end  
        %%% 将图像块分成四部分，从图像的中心向四条边进行搜索
        %%% 计算图像块四个方向的边界
        %%% 计算图像块上边界
        if(Row_coordinate(i,j)-Block_half<1)
            Block_h_down=Row_coordinate(i,j)-1;
            row_down=1;
            row_down_origin=Row_coordinate_origin(i)-Block_h_down;
        else
            row_down=round(Row_coordinate(i,j)-Block_half);
            row_down_origin=round(Row_coordinate_origin(i)-Block_half);
        end
        %%% 计算图像块的下边界
        if(Row_coordinate(i,j)+Block_half>Height)
            Block_h_up=Height-Row_coordinate(i,j);
            row_up=Height;
            row_up_origin=Row_coordinate_origin(i)+Block_h_up;
        else
            row_up=round(Row_coordinate(i,j)+Block_half);
            row_up_origin=round(Row_coordinate_origin(i)+Block_half);
        end
        %%% 如果最下面的图像块比标准的要小，单独计算
        %%% 多出的一部分的下边界
        if(i==N_row && Block_height~=0)
            if(Row_coordinate(i,j)+Block_height>Height)
            Block_h_up=Height-Row_coordinate(i,j);
            row_up=Height;
            row_up_origin=Row_coordinate_origin(i)+Block_h_up;
            else
            row_up=floor(Row_coordinate(i,j)+Block_height);
            row_up_origin=floor(Row_coordinate_origin(i)+Block_height);
            end
        end
        %%% 计算图像的左边界
        if(Col_coordinate(i,j)-Block_half<1)
            Block_w_down=Col_coordinate(i,j)-1;
            col_down=1;
            col_down_origin=Col_coordinate_origin(j)-Block_w_down;
        else
            col_down=round(Col_coordinate(i,j)-Block_half);
            col_down_origin=round(Col_coordinate_origin(j)-Block_half);
        end
        %%计算图像的右边界
        if(Col_coordinate(i,j)+Block_half>Width)
            Block_w_up=Width-Col_coordinate(i,j);
            col_up=Width;
            col_up_origin=Col_coordinate_origin(j)+Block_w_up;
        else
            col_up=round(Col_coordinate(i,j)+Block_half);
            col_up_origin=round(Col_coordinate_origin(j)+Block_half);
        end
        %%% 如果最右边的图像块比标准的要小，单独计算
        %%% 多出的一部分的右边界
        if(j==N_col && Block_width~=0)
            if(Col_coordinate(i,j)+Block_width>Width)
            Block_w_up=Width-Col_coordinate(i,j);
            col_up=Width;
            col_up_origin=Col_coordinate_origin(j)+Block_w_up;
            else
            col_up=floor(Col_coordinate(i,j)+Block_width);
            col_up_origin=floor(Col_coordinate_origin(j)+Block_width);
            end
        end
        Image2(row_down:row_up,col_down:col_up,:) = ...
               Image(row_down_origin:row_up_origin,col_down_origin:col_up_origin,:);
    end
end
imshow(Image2/255);    

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