数字图像处理实验报告三四五精编文档docWord格式文档下载.docx

1、Command窗口显示如下：IMRESIZE Resize image. B = IMRESIZE（A, SCALE） returns an image that is SCALE times the size of A, which is a grayscale, RGB, or binary image. B = IMRESIZE（A, NUMROWS NUMCOLS） resizes the image so that it has the specified number of rows and columns. Either NUMROWS or NUMCOLS may be NaN

2、, in which case IMRESIZE computes the number of rows or columns automatically in order to preserve the image aspect ratio. Y, NEWMAP = IMRESIZE（X, MAP, SCALE） resizes an indexed image. Y, NEWMAP = IMRESIZE（X, MAP, NUMROWS NUMCOLS） resizes an indexed image. To control the interpolation method used by

3、 IMRESIZE, add a METHOD argument to any of the syntaxes above, like this: IMRESIZE（A, SCALE, METHOD） IMRESIZE（A, NUMROWS NUMCOLS, METHOD）, IMRESIZE（X, MAP, M, METHOD） IMRESIZE（X, MAP, NUMROWS NUMCOLS, METHOD） METHOD can be a string naming a general interpolation method: - nearest-neighbor interpolat

4、ion - bilinear interpolationbicubic - cubic interpolation; the default method METHOD can also be a string naming an interpolation kernel:box - interpolation with a box-shaped kerneltriangle - interpolation with a triangular kernel （equivalent to ）cubic - interpolation with a cubic kernel lanczos2 -

5、interpolation with a Lanczos-2 kernellanczos3 - interpolation with a Lanczos-3 kernel Finally, METHOD can be a two-element cell array of the form f,w, where f is the function handle for a custom interpolation kernel, and w is the custom kernels width. f（x） must be zero outside the interval -w/2 = x

6、w/2. Your function handle f may be called with a scalar or a vector input. You can achieve additional control over IMRESIZE by using parameter/value pairs following any of the syntaxes above. For example: B = IMRESIZE（A, SCALE, PARAM1, VALUE1, PARAM2, VALUE2, .） Parameters include:Antialiasing - tru

7、e or false; specifies whether to perform antialiasing when shrinking an image. The default value depends on the interpolation method you choose. For the method, the default is false; for all other methods, the default is true.Colormap - （only relevant for indexed images） original or optimized; if ,

8、then the output newmap is the same as the input map. If it is , then a new optimized colormap is created. The default value is. Dither - （only for indexed images） true or false; specifies whether to perform color dithering. The default value is true.Method - As described aboveOutputSize - A two-elem

9、ent vector, MROWS NCOLS, specifying the output size. One element may be NaN, in which case the other value is computed automatically to preserve the aspect ratio of the image. Scale - A scalar or two-element vector specifying the resize scale factors. If it is a scalar, the same scale factor is appl

10、ied to each dimension. If it is a vector, it contains the scale factors for the row and column dimensions, respectively. Examples - Shrink by factor of two using the defaults of bicubic interpolation and antialiasing. I = imread（rice.png J = imresize（I, 0.5）; figure, imshow（I）, figure, imshow（J） Shr

11、ink by factor of two using nearest-neighbor interpolation. （This is the fastest method, but it has the lowest quality.） J2 = imresize（I, 0.5, Resize an indexed image. X, map = imread（trees.tif Y, newmap = imresize（X, map, 0.5）; imshow（Y, newmap） Resize an RGB image to have 64 rows. The number of col

12、umns is computed automatically. RGB = imread（peppers.png RGB2 = imresize（RGB, 64 NaN）; Note - The function IMRESIZE in previous versions of the Image Processing Toolbox used a somewhat different algorithm by default. If you need the same results produced by the previous implementation, call the func

13、tion IMRESIZE_OLD. Class Support - The input image A can be numeric or logical and it must be nonsparse. The output image is of the same class as the input image. The input indexed image X can be uint8, uint16, or double. See also imresize_old, imrotate, imtransform, tformarray. Reference page in He

14、lp browser doc imresize执行程序所得结果如下：改变参数Scale =0.5得到图形结果如下：对以上实验结果，分析如下：通过查看命令窗口查看imresize函数的使用方法。本实验中利用了形式B = imresize（A,m,method）。实验中method采用了，（默认值）最近邻插值 方法和双线性插值方法，由图片显示结果可以看出，双线性插值方法要好于最近邻插值方法。这是由于最近邻插值方法仅是取离其最近的一个像素的像素值，而双线性插值方法采用了其周围的像素值参与计算，所以更能适应图像的局部特征。m为放大倍数，由上面实验结果可以明显看出，放大1.35倍和0.5倍的效果差异。2

15、. 图像旋转Theta = 45; % 将图像逆时针旋转45。J1 = imrotate（I, Theta, %and enlarge the output imageTheta = -45; % 将图像顺时针旋转45。J2 = imrotate（I, Theta, , crop % using the bilinear interpolation % and crops the output image Rotated Image- using the nearest neighbor interpolation Rotated Image- using the bilinear inter

16、polation % 查看imrotate使用帮助help imrotateIMROTATE Rotate image. B = IMROTATE（A,ANGLE） rotates image A by ANGLE degrees in a counterclockwise direction around its center point. To rotate the image clockwise, specify a negative value for ANGLE. IMROTATE makes the output image B large enough to contain th

17、e entire rotated image. IMROTATE uses nearest neighbor interpolation, setting the values of pixels in B that are outside the rotated image to 0 （zero）. B = IMROTATE（A,ANGLE,METHOD） rotates image A, using the interpolation method specified by METHOD. METHOD is a string that can have one of the follow

18、ing values. The default value is enclosed in braces （）. Nearest neighbor interpolation Bilinear interpolation Bicubic interpolation. Note: This interpolation method can produce pixel values outside the original range. B = IMROTATE（A,ANGLE,METHOD,BBOX） rotates image A, where BBOX specifies the size o

19、f the output image B. BBOX is a text string that can have either of the following values. The default value is enclosed in braces （）.loose Make output image B large enough to contain the entire rotated image. B is generally larger than A. Make output image B the same size as the input image A, cropp

20、ing the rotated image to fit. The input image can be numeric or logical. The output image is of the same class as the input image. Example - % This example brings image I into horizontal alignment by % rotating the image by -1 degree. I = fitsread（solarspectra.fts I = mat2gray（I）; J = imrotate（I,-1,

21、 See also imcrop, imresize, imtransform, tformarray. doc imrotate改变参数，Theta = 135和-135时，所得结果如下：实验结果分析如下：通过查看命令窗口了解imrotate函数的使用。本实验中采用了函数的两种形式，B = imrotate（A,angle,method）和B = imrotate（A,angle,method,bbox）。实验中，method的设置及其原理同上个实验。实验中，bbox设置为了“crop”,其作用是为了使输出图像和输入图像大小相同，可以看出当设置了该参数是，图像明显被裁减了，这是因为图像旋转后

22、面积变大了，而该参数的设置使图像须保持原来的大小i，因而图像被裁减了，未设置该参数时默认大小可以显示整个旋转后的图像。Angle为旋转角度，分别设置为了45和-45、135和-135，由上面两组图可以看出明显的效果和差异 3图像水平镜象I1 = flipdim（I,2）;I2 = flipdim（I,1）;figure（1）, subplot（1,2,1）, imshow（I）;subplot（1,2,2）, imshow（I1）;figure（2）, subplot（2,1,1）, imshow（I）;subplot（2,1,2）, imshow（I2）;执行程序，所得结果如下：对实验结果分

23、析如下：flipdim 函数的使用方法如下。B = flipdim（A,dim）沿指定的维翻转矩阵。当dim=1时，行翻转，等同于flipud ，当dim=2时，列翻转，等同于fliplr 。由上图可以看出翻转的效果。（二）用MATLAB编程实现以下图像几何变换1图像平移 程序代码如下： clc,clear all;rows=size（I,1）;cols=size（I,2）;movx=50;movy=50;for i=1:rows for j=1:cols Q（i+movx,j+movy）=I（i,j）; endendfigure（1）;subplot（121）;imshow（I）;title

24、（origine picturesubplot（122）;imshow（Q）;modified picture执行程序结果如下：实验分析如下：实验中，每个像素值以及其对应的坐标x和y都被平移了50，表现在整个图像上，即向右下角平移sqrt（50*50+50*50）,显示结果如上图所示。2图像转置图像的转置是将给定图像像素的x坐标和y坐标互换的几何变换，设点P0（x0, y0） 转置后的对应点为P（x, y），转置变换可表述为： 或 ，对应的逆变换为：转置后图像的宽、高发生改变，即输出图像的高度为原始图像的宽度，输出图像的宽度为原始图像的高度。 Q（j,i）=I（i,j）;size（I）,siz

25、e（Q） 执行程序，所得结果如下： 设图像中某个像素为p（j,i），则其值为被p（i,j）被代替,其中p为整个图像的像素矩阵。对图像中的所有像素.逐列、逐行的进行此计算，即可实现转置。实验结果如上图所示，明显看出，转置后图像的宽、高发生改变，即输出图像的高度为原始图像的宽度，输出图像的宽度为原始图像的高度，整个图像被“转置”了。三、实验设备1PIII以上微机；2MATLAB6.5；四、实验心得与体会实验四 图像形态学处理1利用MATLAB研究二值形态学图像处理常用算法；2掌握MATLAB形态学图像处理基本操作函数的使用方法；3了了解形态学的基本应用。1膨胀与腐蚀（Dilation and Erosion）（1）对简单二值图像进行膨胀与腐蚀BW = zeros（9,10）;BW（4:6,4:7） = 1;BW;SE = strel（square,3） BW