彩色图像转化为灰色图像,再锐化的一个实验

ｍａｔｌａｂ命令代码；

 

 

>> info=imfinfo('plane.jpg')

info =

           Filename: 'plane.jpg'
        FileModDate: '16-May-2009 10:09:02'
           FileSize: 15503
             Format: 'jpg'
      FormatVersion: ''
              Width: 640
             Height: 480
           BitDepth: 24
          ColorType: 'truecolor'
    FormatSignature: ''
    NumberOfSamples: 3
       CodingMethod: 'Huffman'
      CodingProcess: 'Sequential'
            Comment: {}

>> i=imread('plane.jpg');
>> imshow(i)
>> y=rgb2gray(i);
>> figure,imshow(y);
>> g=[-1 -1 -1; -1 8-1; -1-1-1];
??? Error using ==> vertcat
All rows in the bracketed expression must have the same
number of columns.

>> g=[-1 -1 -1; -1 8 -1 ;-1 -1 -1];
>> h=double(i);
>> j=conv2(h,g,'same');
??? Function 'conv2' is not defined for values of class 'double' and attributes 'full 3d real'.

>> j=conv2(i,g,'same');
Warning: CONV2 on values of class UINT8 is obsolete.
         Use CONV2(DOUBLE(A),DOUBLE(B)) or CONV2(SINGLE(A),SINGLE(B)) instead.
> In uint8.conv2 at 11
??? Function 'conv2' is not defined for values of class 'double' and attributes 'full 3d real'.

Error in ==> uint8.conv2 at 20 （ 原因在于ｒｇｂ图像是三维数组，而ｃｏｎｖ是二位操作，所以必须先转化为灰度图像）
y = conv2(varargin{:});

>> help conv2
CONV2 Two dimensional convolution.
    C = CONV2(A, B) performs the 2-D convolution of matrices
    A and B.   If [ma,na] = size(A) and [mb,nb] = size(B), then
    size(C) = [ma+mb-1,na+nb-1].
    C = CONV2(H1, H2, A) convolves A first with the vector H1
    along the rows and then with the vector H2 along the columns.
    C = CONV2(..., SHAPE) returns a subsection of the 2-D
    convolution with size specified by SHAPE:
      'full'  - (default) returns the full 2-D convolution,
      'same'  - returns the central part of the convolution
                that is the same size as A.
      'valid' - returns only those parts of the convolution
                that are computed without the zero-padded
                edges. size(C) = [ma-mb+1,na-nb+1] when
                all(size(A) >= size(B)), otherwise C is
                an empty matrix [].
    If any of A, B, H1, and H2 are empty, then C is
    an empty matrix [].
    See also conv, convn, filter2 and, in the Signal Processing
    Toolbox, xcorr2.

    Overloaded functions or methods (ones with the same name in other directories)
       help uint8/conv2.m
       help uint16/conv2.m

    Reference page in Help browser
       doc conv2

>> j=conv2(y,g,'same');
Warning: CONV2 on values of class UINT8 is obsolete.
         Use CONV2(DOUBLE(A),DOUBLE(B)) or CONV2(SINGLE(A),SINGLE(B)) instead.
> In uint8.conv2 at 11
>> h=double(y); j=conv2(h,g,'same');
>> figure ,imshow(h);title('原始图像');
>> figure ,imshow(j);title('原始图像');
>> h=double(y);
>>  j=conv2(h,g,'same');
>> figure ,imshow(j);title('原始图像');
>> j=conv2(y,g,'same');
Warning: CONV2 on values of class UINT8 is obsolete.
         Use CONV2(DOUBLE(A),DOUBLE(B)) or CONV2(SINGLE(A),SINGLE(B)) instead.
> In uint8.conv2 at 11
>> figure ,imshow(j);title('zhuangh图像');
>> H=fspecial('sobel');
>> I2=filter2(H,y);
>> figure,imshow(I2);
>> imwrite(y,'plane.bmp','bmp');
>> info=imfinfo('plane.bmp');
>> info （结果不尽人意，于是，我保存后检查一下图像格式，发现是'indexed' ，有点疏忽，应该调用ｉｓｇｒａｙ命令来分析更好）

info =

              Filename: 'plane.bmp'
           FileModDate: '16-May-2009 11:03:44'
              FileSize: 308278
                Format: 'bmp'
         FormatVersion: 'Version 3 (Microsoft Windows 3.x)'
                 Width: 640
                Height: 480
              BitDepth: 8
             ColorType: 'indexed'
       FormatSignature: 'BM'
    NumColormapEntries: 256
              Colormap: [256x3 double]
               RedMask: []
             GreenMask: []
              BlueMask: []
       ImageDataOffset: 1078
      BitmapHeaderSize: 40
             NumPlanes: 1
       CompressionType: 'none'
            BitmapSize: 307200
        HorzResolution: 0
        VertResolution: 0
         NumColorsUsed: 256
    NumImportantColors: 0