Image Processing Toolbox For Use with MATLAB ® Computation Visualization Programming User’s Guide Version How to Contact The MathWorks: www.mathworks.com comp.soft-sys.matlab Web Newsgroup info@mathworks.com Technical support Product enhancement suggestions Bug reports Documentation error reports Order status, license renewals, passcodes Sales, pricing, and general information 508-647-7000 Phone 508-647-7001 Fax The MathWorks, Inc Apple Hill Drive Natick, MA 01760-2098 Mail support@mathworks.com suggest@mathworks.com bugs@mathworks.com doc@mathworks.com service@mathworks.com For contact information about worldwide offices, see the MathWorks Web site Image Processing Toolbox User’s Guide  COPYRIGHT 1993 - 2001 by The MathWorks, Inc The software described in this document is furnished under a license agreement The software may be used or copied only under the terms of the license agreement No part of this manual may be photocopied or reproduced in any form without prior written consent from The MathWorks, Inc FEDERAL ACQUISITION: This provision applies to all acquisitions of the Program and Documentation by or for the federal government of the United States By accepting delivery of the Program, the government hereby agrees that this software qualifies as "commercial" computer software within the meaning of FAR Part 12.212, DFARS Part 227.7202-1, DFARS Part 227.7202-3, DFARS Part 252.227-7013, and DFARS Part 252.227-7014 The terms and conditions of The MathWorks, Inc Software License Agreement shall pertain to the government’s use and disclosure of the Program and Documentation, and shall supersede any conflicting contractual terms or conditions If this license fails to meet the government’s minimum needs or is inconsistent in any respect with federal procurement law, the government agrees to return the Program and Documentation, unused, to MathWorks MATLAB, Simulink, Stateflow, Handle Graphics, and Real-Time Workshop are registered trademarks, and Target Language Compiler is a trademark of The MathWorks, Inc Other product or brand names are trademarks or registered trademarks of their respective holders Printing History: August 1993 May 1997 January 1998 January 1999 September 2000 April 2001 First printing Version Second printing Version Revised for Version 2.1 (Online only) Revised for Version 2.2 (Release 11) (Online only) Revised for Version 2.2.2 (Release 12) (Online only) Third Printing Version 3.0 Image Credits moon Copyright Michael Myers Used with permission cameraman Copyright Massachusetts Institute of Technology Used with permission trees Trees with a View, watercolor and ink on paper, copyright Susan Cohen Used with permission forest Photograph of Carmanah Ancient Forest, British Columbia, Canada, courtesy of Susan Cohen circuit Micrograph of 16-bit A/D converter circuit, courtesy of Steve Decker and Shujaat Nadeem, MIT, 1993 m83 M83 spiral galaxy astronomical image courtesy of Anglo-Australian Observatory, photography by David Malin cell Cancer cellfrom a rat’s prostate, courtesy of Alan W Partin, M.D., Ph.D., Johns Hopkins University School of Medicine LAN files Permission to use Landsat™ data sets provided by Space Imaging, LLC, Denver, Colorado concordorthophoto and westconcordorthophoto Orthoregistered photographs courtesy of Massachusetts Executive Office of Environmental Affairs, MassGIS concordaerial and westconcordaerial Visible color aerial photographs courtesy of mPower3/Emerge alumgrns bacteria blood1 bonemarr circles circlesm debye1 enamel flowers ic lily ngc4024l ngc4024m ngc4024s rice saturn shot1 testpat1 testpat2 text tire Copyright J C Russ, The Image Processing Handbook, Second Edition, 1994, CRC Press, Boca Raton, ISBN 0-8493-2516-1 Used with permission Contents Getting Started Preface What Is the Image Processing Toolbox? xxv R12 Related Products List xxvi Configuration Notes xxviii About This Manual xxix Words You Need to Know xxx Typographical Conventions xxxi Image Processing Demos xxxiii MATLAB Newsgroup xxxvii Getting Started Overview 1-2 Exercise — Some Basic Topics Read and Display an Image Check the Image in Memory Perform Histogram Equalization Write the Image Check the Contents of the Newly Written File 1-3 1-3 1-3 1-4 1-7 1-8 vi Exercise — Advanced Topics Read and Display an Image Use Morphological Opening to Estimate the Background Display the Background Approximation as a Surface Subtract the Background Image from the Original Image Adjust the Image Contrast Apply Thresholding to the Image Determining the Number of Objects in the Image Examine an Object Measure Object Properties in the Image 10 Compute Statistical Properties of Objects in the Image 1-10 1-10 1-10 1-11 1-13 1-14 1-15 1-16 1-19 1-20 1-22 Where to Go from Here 1-25 Online Help 1-25 Toolbox Demos 1-25 Using the Image Processing Toolbox Introduction Overview 2-2 Words You Need to Know 2-2 Images in MATLAB and the Image Processing Toolbox 2-4 Storage Classes in the Toolbox 2-4 Image Types in the Toolbox 2-5 Indexed Images 2-5 Intensity Images 2-7 Binary Images 2-8 RGB Images 2-9 Multiframe Image Arrays 2-12 Summary of Image Types and Numeric Classes 2-13 Converting Image Types 2-14 vii Contents Working with Image Data Reading a Graphics Image Writing a Graphics Image Querying a Graphics File Converting Image Storage Classes Converting Graphics File Formats 2-17 2-18 2-19 2-20 2-21 2-22 Image Arithmetic Summary of Image Arithmetic Functions Image Arithmetic Truncation Rules Adding Images Subtracting Images Multiplying Images Dividing Images Nesting Calls to Image Arithmetic Functions 2-23 2-24 2-24 2-25 2-26 2-28 2-29 2-30 Coordinate Systems 2-31 Pixel Coordinates 2-31 Spatial Coordinates 2-32 Displaying and Printing Images Overview 3-2 Words You Need to Know 3-2 Displaying Images with imshow 3-3 Displaying Indexed Images 3-3 Displaying Intensity Images 3-4 Displaying Binary Images 3-6 Displaying RGB Images 3-11 Displaying Images Directly from Disk 3-13 Special Display Techniques Adding a Colorbar Displaying Multiframe Images Displaying Multiple Images 3-14 3-14 3-15 3-19 viii Setting the Preferences for imshow 3-24 Zooming in on a Region of an Image 3-26 Texture Mapping 3-28 Printing Images 3-29 Troubleshooting 3-30 Spatial Transformations Overview 4-2 Words You Need to Know 4-2 Interpolation 4-4 Image Types 4-5 Image Resizing 4-6 Image Rotation 4-8 Image Cropping 4-9 Performing General Spatial Transformations Specifying the Transformation Type Performing the Transformation Advanced Spatial Transformation Techniques 4-11 4-11 4-13 4-14 Image Registration Overview 5-2 Words You Need to Know 5-3 ix Contents Registering an Image 5-5 Example: Registering to a Digital Orthophoto 5-6 Types of Supported Transformations 5-13 Selecting Control Points Using the Control Point Selection Tool Starting the Control Point Selection Tool Viewing the Images Specifying Matching Control Point Pairs Saving Control Points 5-15 5-15 5-16 5-18 5-22 5-29 Using Correlation to Improve Control Points 5-32 Neighborhood and Block Operations Overview 6-2 Words You Need to Know 6-2 Types of Block Processing Operations 6-3 Sliding Neighborhood Operations 6-4 Padding of Borders 6-5 Linear and Nonlinear Filtering 6-5 Distinct Block Operations 6-8 Overlap 6-9 Column Processing 6-11 Sliding Neighborhoods 6-11 Distinct Blocks 6-12 x Index zooming 3-26 distance between pixels 10-4 Euclidean 10-4 distance transform 9-39 distinct block operations 6-8 definition 6-2 overlap 6-9, 14-23 zero padding 6-8 dither 14-106 dithering 13-14, 14-106, 14-336 example 13-14 division of images 2-29 double 2-21, 14-107, 14-170, 14-184, 14-195, 14-228, 14-231, 14-261 E edge 10-11, 14-108 example 10-11 See also edgedemo edge detection 10-11 Canny method 10-11 demo of xxxiii example 10-11 methods 14-108 Sobel method 10-11 edgedemo demo application xxxiii edges definition 10-2 edgetaper 14-113 edgetaper avoiding boundary ringing 12-13 enhancing images intensity adjustment 10-15, 14-171 noise removal 10-21 I-10 erode 14-114 erosion 9-5, 14-52, 14-114 grayscale 14-308 Euclidean distance 10-4, 14-317 Euler number 9-53, 14-38 F fan beam projections 8-29 fast Fourier transform 8-9 higher-dimensional 14-118 higher-dimensional inverse 14-161 two-dimensional 14-116 two-dimensional inverse 14-160 zero padding 8-11 feature measurement 14-203 area 10-10 binary images 9-50 bounding box 1-22, 10-10 center of mass 10-10 feature measurements 1-20 feature-based logic demo of xxxv fft 8-9 fft2 2-17, 8-9, 14-116, 14-369 example 8-10, 8-12 fftn 2-17, 8-9, 14-118, 14-369 fftshift 14-119 example 7-17, 8-12 file formats 14-243, 14-270 graphics formats 2-18 file size querying 14-216 files displaying images from disk 3-13 reading image data from 14-243 writing image data to 14-270 Index filling a region 11-9 definition 11-2 demo of xxxvi filling holes in images 9-29 filter design 7-16 frequency sampling method 7-18, 14-127 frequency transformation method 7-17, 14-135 windowing method 7-19, 14-138, 14-142 filter2 14-120 compared to imfilter 7-14 example 3-5, 3-14, 10-23 filtering a region 11-7 masked filtering 11-7 regions 11-2 filters adaptive 10-24, 14-376 averaging 14-130 binary masks 11-7 designing 7-16 finite impulse response (FIR) 7-16 frequency response 7-21, 8-12 imfilter 7-7 Infinite Impulse Response (IIR) 7-17 Laplacian of Gaussian 14-130 linear 7-4, 14-120 median 10-22, 14-301 multidimensional 7-13 order-statistic 14-308 predefined types 14-130 Prewitt 14-130 regularized demo xxxiv Sobel 14-130 unsharp 14-130 unsharp masking 7-14 FIR filters 7-16 demo of xxxiii transforming from one-dimensional to two-dimensional 7-17 firdemo demo application xxxiii flood-fill operation 9-27, 14-40 foreground of a binary image 9-3 fast Fourier transform See also Fourier transform Fourier transform 8-4 applications of the Fourier transform 8-12 centering the zero-frequency coefficient 8-12 computing frequency response 8-12 convolution and 8-13 correlation 8-14 DFT coefficients 8-10 examples of transform on simple shapes 8-8 fast convolution with 8-13 for performing correlation 8-14 frequency domain 8-4 higher-dimensional 14-118 higher-dimensional inverse 14-161 increasing resolution 8-11 padding before computation 8-11 rearranging output 14-119 two-dimensional 8-4, 14-116 two-dimensional inverse 14-160 zero-frequency component component freqspace 7-20, 14-124 example 7-18, 7-20, 7-21 frequency domain 8-4 definition 8-3 frequency response computing 7-21, 8-12, 14-125 desired response matrix 7-20, 14-124 frequency sampling method (filter design) 7-18, 14-127 I-11 Index frequency transformation method (filter design) 7-17, 14-135 freqz example 7-17 freqz2 7-21, 8-12, 14-125 example 7-18, 7-20, 7-22 See also firdemo fsamp2 7-18, 14-127 example 7-18 See also firdemo fspecial 14-130 fspecial creating predefined filters 7-14 ftrans2 14-135 example 7-17 See also firdemo function functions passing a string to A-4 passing an M-file to A-3 using A-2 using inline objects with A-4 function handles A-2 funfun A-2 fwind1 7-19, 14-138 example 7-20 See also firdemo fwind2 7-19, 14-142 See also firdemo Gaussian noise 10-24 geocoded images 5-7 geometric operations cropping 4-9, 14-188 definition 4-3 interpolation 4-4 resizing 4-6, 14-255 rotation 4-8, 14-257 georegistered images 5-7 getheight 14-146 getimage 14-147 example 3-13 getneighbors 14-149 getnhood 14-150 getsequence 14-151 GIF bit depths supported when reading 14-246 granulometry demo xxxiv graphics card 13-5 graphics file formats converting from one format to another 2-22 list of formats supported by MATLAB 2-18 See also BMP, HDF, JPG, PCX, PNG, TIFF, XWD gray2ind 14-152 grayscale imagesSeeintensity images grayscale morphological operations 14-308 grayslice 14-153 graythresh 14-154 G gamma correction 10-17 demo of xxxiv See also imadjust Gaussian convolution kernel frequency response of 8-12 Gaussian filter 14-130 I-12 thresholding image values 1-15 H HDF 2-18, 14-215, 14-243, 14-271 appending to when saving (WriteMode) 14-271 bit depths supported when reading 14-247 Index bit depths supported when writing 14-275 compression 14-271 parameters that can be set when writing 14-271 reading with special imread syntax 14-246 setting JPEG quality when writing 14-271 head phantom image 8-30 histeq 14-155 example 10-20 increase contrast example 10-19 See also imadjdemo and roidemo histogram equalization 10-19, 14-155 demo of xxxiv histograms 10-9, 14-218 definition 10-3 demo of xxxiv holes filling 9-27 HSV color space 13-18, 14-158, 14-335 color planes of 13-19, 13-20 hsv2rgb 13-18, 14-158 hue in HSV color space 13-17 in NTSC color space 13-16 I ICO bit depths supported when reading 14-247 icon images 14-246 idct2 14-159 See also dctdemo ifft 8-9 ifft2 8-9, 14-160 ifftn 8-9, 14-161 IIR filters 7-17 im2bw 2-15, 14-162 im2col 14-164 See also dctdemo im2double 2-21, 14-165 example 6-14 See also dctdemo and ipss003 im2mis 14-166 im2uint16 2-21, 14-168, 14-168 im2uint8 2-21, 14-167 imabsdiff 14-169 imadjdemo demo application xxxiv imadjust 10-15, 14-171 brightening example 10-16 gamma correction and 10-17 gamma correction example 10-18 increase contrast example 10-15 See also imadjdemo, landsatdemo, roidemo, and ipss003 image analysis contour plots 10-9 edge detection 10-11 histograms 10-9 intensity profiles 10-5 overview 10-11 pixel values 10-4 quadtree decomposition 10-12 summary statistics 10-10 image area (binary images) 14-27 image arithmetic combining functions 2-30 example 9-44 overview 2-23 truncation rules 2-24 image editing 11-9 image filtering data types 7-7 unsharp masking 7-14 with imfilter 7-7 I-13 Index image processing demos xxxiii–xxxvi See also demos image profiles definition 10-3 image properties definition 10-2 set by imshow 3-4 set by imshow for binary images 3-11 set by imshow for intensity images 3-6 set by imshow for RGB images 3-12 image registration demo xxxiv fine-tuning point placement 5-32 overview 5-2 procedure 5-5 selecting control points 5-15 specifying control point pairs 5-22 types of transformations 5-13 using control point prediction 5-25 image transformations affine 5-13 custom 4-11 demos xxxv gallery of examples xxxv local weighted mean 5-14 piecewise linear 5-14 polynomial 5-14 projective 5-14 supported by cp2tform 5-13 types of 5-13 using imtransform 4-11 image types 2-5 binary 2-8 converting between 2-14 indexed 2-5 intensity 2-7 I-14 multiframe images 2-12 overview 2-2 querying 14-216 RGB 2-9 See also indexed, intensity, binary, RGB, multiframe supported by the toolbox 2-5 images adding 2-25 analyzing 10-4 arithmetic operations 2-23 as Handle Graphics objects 1-12 causes of blurring 12-3 color 13-2 converting to binary 14-162 data types 2-4, 14-107, 14-169, 14-170, 14-195, 14-231, 14-261, 14-367, 14-369 displaying 3-2, 14-259 displaying multiple images 3-19, 14-357 dividing 2-29 feature measurement 1-20 file formats 14-243, 14-270 filling holes in 9-29 finding image minima and maxima 9-30 getting data from axes 14-147 how MATLAB stores 2-4 image types 2-5 improving contrast 1-14 multiplication 2-28 reading data from files 14-243 reducing number of colors 13-7, 14-174 registering 5-5 restoring blurred images 12-2 returning information about 2-20 sample images 1-2 statistical analysis of 1-22 storage classes of 2-4 Index subtraction 2-26 viewing as a surface plot 1-11 writing to files 14-270 imapprox 13-13, 14-174 example 13-13 imbothat 14-175 imbothat example 9-43 See also ipexsegwatershed demo imclearborder 14-177 imclose 14-180 imclose See also ipexsegmicro demo using 9-15 correlation option 7-9 padding options 7-10 using 7-7 imfinfo 2-20 example 3-9 returning file information 14-215 imhist 10-9, 14-218 example 10-10, 10-15 See also imadjdemo imhmax 14-220 imhmin 14-222 imimposemin 14-224 imlincomb example 2-30 imcomplement immovie 14-230 example 9-45 imcontour 10-9, 14-186 example 10-9 imcrop 4-9, 14-188 example 4-9 imdilate 14-191 imerode 14-196 closure example 9-16 imextendedmax 14-199 example 3-18 imnoise 10-22, 14-232 example 10-24 salt & pepper example 10-22 See also nrfiltdemo and roidemo imopen imfill 14-209 See also ipexsegmicro demo using 9-15 impixel 10-4, 14-237 example 10-5 improfile 10-5, 14-240 example 10-7 grayscale example 10-6 imread 2-18, 14-243 example for multiframe image 3-16 imreconstruct 14-249 imfill imreconstruct imextendedmax example 9-32 imextendedmin 14-201 imextendedmin example 9-46 imfeature 14-203 example 9-29 example 9-21 imfilter 14-212 imregionalmax 14-251 imfilter imregmin 14-253 compared to other filtering functions 7-14 convolution option 7-9 imresize 4-6, 14-255 imrotate 14-257 I-15 Index example 4-6, 4-8 imshow 3-25, 14-259 example for binary images 3-6 example for indexed images 3-3 example for intensity images 3-4, 3-5 example for RGB images 3-12 notruesize option 3-8 preferences for 3-25 truesize option 3-26 imtophat 14-262 imtophat example 9-43 See also ipexsegwatershed demo imtransform 14-234, 14-264 See also ipextform demo using 4-11 imwrite 14-270 example 3-9 ind2gray 14-277 ind2rgb 2-15, 14-278 example 3-22 indexed images 2-5, 14-288 converting from intensity 14-152 converting from RGB 14-336 converting to intensity 14-277 converting to RGB 14-278 definition 2-2 displayed as intensity image 3-30 reducing number of colors 13-7 reducing number of colors in 13-13 infinite impulse response (IIR) filter 7-17 information returning file information 14-215 inline 6-9, A-4 See also function functions inline object I-16 passing an inline object to a function function A-4 intensity adjustment 10-15, 14-171 gamma correction 10-17 histogram equalization 10-19 See also contrast adjustment intensity images 2-7, 14-287 converting from indexed 14-277 converting from matrices 14-299 converting from RGB 14-334 converting to indexed 14-152 definition 2-3 displaying 3-4 flood-fill operation 9-27 number of gray levels displayed 3-5 intensity profiles 10-5, 14-240 interpolation 4-4 bicubic 4-4 definition 4-3 bilinear 4-4 definition 4-3 definition 4-3 intensity profiles 10-5 nearest neighbor 4-4 definition 4-3 of binary images 4-5 of indexed images 4-5 of RGB images 4-5 tradeoffs between methods 4-4 within a region of interest 11-9 inverse Radon transform 8-27, 8-29 example 8-33 filtered backprojection algorithm 8-29 inverse transform definition 8-3 ipss001 demo slideshow xxxv ipss002 demo slideshow xxxv Index ipss003 demo slideshow xxxiv, xxxv iptgetpref 3-25, 14-279 iptsetpref 3-25, 14-280 example 3-25, 3-26 iradon 8-27, 14-282 example 8-27 isbw 14-285 isflat 14-286 isgray 14-287 isind 14-288 isrgb 14-289 J JPEG 2-18 JPEG compression discrete cosine transform and 8-19 JPEG files 14-215, 14-243, 14-271 bit depths supported when reading 14-247 bit depths supported when writing 14-275 parameters that can be set when writing 14-272 JPEG quality setting when writing a JPEG image 14-272 setting when writing an HDF image 14-271 L labeling connected-components 9-50 levels of contours 10-9 Laplacian of Gaussian edge detector 14-109 Laplacian of Gaussian filter 14-130 line detection 8-25 line segment pixel values along 10-5 linear conformal transformations 5-13 linear filtering 6-5, 7-4, 14-120 convolution 7-4 filter design 7-16 FIR filters 7-16 IIR filters 7-17 noise removal and 10-22 local weighted mean transformations 5-14 logical arrays 2-8, 2-22 logical flag 2-8 lookup table operations 9-54 lookup-table operations 14-290 Lucy-Richardson algorithm demo xxxiv used for deblurring 12-10 luminance in NTSC color space 13-16 in YCbCr color space 13-17 M magnifying See resizing images makelut 9-54, 14-290 example 9-54 marker controlled watershed segmentation example 9-42 marker image creating 9-36 definition 9-20 mask image definition 9-20 masked filtering 11-7, 14-344 definition 11-3 mat2gray 2-15, 14-299 MATLAB Newsgroup xxxvii matrices converting to intensity images 14-299 I-17 Index storing images in 2-4 maxima finding in images 9-30 imposing 9-35 suppressing 9-33 McClellan transform 14-135 mean2 10-10, 14-300 medfilt2 10-22, 14-301 example 10-23 See also nrfiltdemo and roidemo median filtering 10-22, 14-301 minima finding in images 9-30 imposing 9-35 suppressing 9-33 minimum variance quantization See quantization Moiré patterns 4-7 montage 14-303 example 3-17 morphological closing demo xxxv morphological opening demo xxxv morphological operations 9-5, 14-51 closing 14-51 diagonal fill 14-52 dilation 9-5, 14-52, 14-104 erosion 9-5, 14-52, 14-114 grayscale 14-308 opening 14-52 predefined operations 9-17 removing spur pixels 14-52 shrinking objects 14-52 skeletonization 9-18, 14-52 thickening objects 14-53 thinning objects 14-53 I-18 morphological reconstruction finding peaks and valleys 9-30 overview 9-20 morphology closing 9-15 definition 9-3 demos xxxiv opening 9-15 overview 9-2 See also morphological reconstruction watershed demo xxxv mouse filling region of interest in intensity image 11-9 getting an intensity profile with 10-4 returning pixel values with 10-4 selecting a polygonal region of interest 11-4 movies creating from images 3-18, 14-230 playing 3-19 MRI data demo xxxiv multidimensional filters 7-13 multiframe images about 2-12 definition 2-3 displaying 3-15, 14-303 limitations 2-12 troubleshooting display of 3-30 multilevel thresholding 14-153 multiplication of images 2-28 N nearest neighbor interpolation 4-4 definition 4-3 neighborhood operations Index definition 6-3 neighborhoods binary image operations 14-20 definition 9-3 neighborhood operations 6-2 nlfilter 6-6, 14-305 example 6-6 noise definition 10-3 noise removal 10-21 adaptive filtering (Weiner) and 10-24 adding noise 14-232 demo of xxxvi Gaussian noise 10-24, 14-232 grain noise 10-22 linear filtering and 10-22 localvar noise 14-232 median filter and 10-22 poisson noise 14-232 salt and pepper noise 10-22, 14-232 speckle noise 14-232 nonlinear filtering 6-5 nonuniform illumination demo of correcting for xxxv normalized cross-correlation 5-32 demo xxxiv normxcorr2 14-306 notruesize option 3-8 nrfiltdemo demo application xxxvi NTSC color space 13-16, 14-307, 14-338 ntsc2rgb 13-16, 14-307 O object selection 14-59 observed image in image registration 5-15 opening 14-52 morphology 9-15 opening an image demo xxxv optical transfer function (OTF) definition 12-2 order-statistic filtering 14-308 ordfilt2 14-308 orthonormal matrix 8-19 orthophoto defined 5-7 orthorectified image 5-7 OTF See optical transfer function otf2psf 14-310 otf2psf use of 12-12 outliers 10-22 overlap in block operations 6-3 in distinct block operations 6-8 P packed binary image definition 9-3 padarray 14-311 padding demo xxxv padding borders block processing 6-5 options with imfilter 7-10 parallel beam projections 8-28 PCX 2-18, 14-215, 14-243, 14-271 bit depths supported when reading 14-247 bit depths supported when writing 14-275 perimeter determination 14-57 I-19 Index in binary images 9-18 phantom 8-30, 14-314 piecewise linear transformations 5-14 pixel values 14-237, 14-317 along a line segment 10-5 returning using a mouse 10-4 pixels defining connectivity 9-24 definition 2-4 displaying coordinates of 10-4 Euclidean distance between 10-4 returning coordinates of 10-4 selecting 10-4 pixval 14-317 pixval 10-4 plotting colormap values 14-340 PNG 2-18 bit depths supported when reading 14-247 bit depths supported when writing 14-275 reading with special imread syntax 14-244 writing as 16-bit 2-19 writing options for 14-272 alpha 14-274 background color 14-274 chromaticities 14-274 gamma 14-274 interlace type 14-273 resolution 14-274 significant bits 14-274 transparency 14-273 point mapping for image registration 5-5 point spread function importance of in deblurring 12-3 point spread function (PSF) definition 12-2 polygon I-20 pixels inside 11-4 selecting a polygonal region of interest 11-4 polynomial transformations 5-14 predicting control point locations in image registration 5-25 preferences getting values 14-280 ImshowAxesVisible 3-25 ImshowBorder 3-25 ImshowTruesize 3-25 TrueSizeWarning 3-25 Prewitt edge detector 14-109 Prewitt filter 14-130 profile 10-4 projections fan beam 8-29 parallel beam 8-28 projective transformations 4-11, 5-14 PSF See point spread function psf2otf 14-318 psf2otf use of 12-12 Q qtdecomp 10-12, 14-319 example 10-13 See also qtdemo qtdemo demo application xxxvi qtgetblk 14-322 See also qtdemo qtsetblk 14-324 See also qtdemo quadtree decomposition 10-12, 14-319 definition 10-3 demo of xxxvi Index getting block values 14-322 setting block values 14-324 quantization 13-8 minimum variance quantization 14-336 trade-offs between using minimum variance and uniform quantization methods 13-12 uniform quantization 14-336 R radon 8-21, 8-27, 14-325 example 8-23 Radon transform 8-21, 14-325 center pixel 8-23 detecting lines 8-25 example 8-30 inverse 14-282 inverse Radon transform 8-27 line detection example 8-25 of the Shepp-Logan Head phantom 8-31 relationship to Hough transform 8-25 rank filtering 10-23 See also order-statistic filtering real orthonormal matrix 8-19 reconstruction morphological 9-20 reference image in image registration 5-15 reflect 14-327 regcorr 14-122, 14-123, 14-292 region labelling 9-50 See connected-components labelling region of interest based on color or intensity 11-6 binary masks 11-4 definition 11-3 demo of xxxvi filling 11-9, 14-342 filtering 11-7, 14-344 polygonal 11-4 selecting 11-4, 11-5, 14-341, 14-346 region property measurement 10-10 regional maxima definition 9-4, 9-30 imposing 9-35 suppressing 9-33 regional minima definition 9-4, 9-30 imposing 9-35 suppressing 9-33 regionprops 10-10, 14-328 using 1-20 regionprops example 9-48 registering an image 5-5 regularized filter demo xxxiv used for deblurring 12-8 replication to avoid border effect 7-12 resizing images 4-6, 14-255 anti-aliasing 4-7 resolution screen color resolution 13-4 See also bit depth 13-4 RGB color cube a description of 13-8 quantization of 13-9 RGB images 2-9, 14-289 converting from indexed 14-278 converting to indexed 14-336 converting to intensity 14-334 I-21 Index definition 2-3 displaying 3-11 intensities of each color plane 10-8 reducing number of colors 13-7 rgb2gray 2-15, 14-334 rgb2hsv 13-18, 14-335 example 13-19 rgb2ind 2-15, 13-8, 14-336 colormap mapping example 13-13 example 13-10, 13-11, 13-13, 13-14 minimum variance quantization example 13-11 specifying a colormap to use 13-12 uniform quantization example 13-10 rgb2ntsc 13-16, 14-338 example 13-16 rgb2ycbcr 13-17 example 13-17 rgbplot 14-340 Richardson-Lucy algorithm See Lucy-Richardson ringing in image deblurring 12-13 Roberts edge detector 14-109 roicolor 11-6, 14-341 roidemo demo application xxxvi, 11-2 roifill 11-9, 14-342 example 11-9 See also roidemo roifilt2 11-7, 14-344 contrast example 11-7 inline example 11-7 See also roidemo roipoly 11-4, 11-5, 14-346 example 11-4 See also roidemo rotating an image 4-8, 14-257 I-22 rotation angle demo of finding xxxiv S salt and pepper noise 10-22 sample images 1-2 saturation in HSV color space 13-17 in NTSC color space 13-16 scale demo of finding xxxiv screen bit depth 3-20, 13-4 definition 13-3 See also ScreenDepth property screen color resolution 13-4 definition 13-3 ScreenDepth 13-4 segmentation demo xxxv shearing demo xxxv Shepp-Logan head phantom 8-30 shrinking See resizing images Signal Processing Toolbox hamming function 7-20 skeletonization 9-18 slideshow demos xxxv sliding neighborhood operations 6-4, 14-305 center pixel in 6-4 padding in 6-5 Sobel edge detector 14-108 Sobel filter 14-130 spatial coordinates 2-32 spatial domain Index definition 8-3 statistical properties mean 14-300 of image objects 1-22 standard deviation 14-348 std2 10-10, 14-348 storage classes converting between 2-21 of images 2-3 strel 14-349 stretchlim 14-355 adjusting image contrast 1-14 structuring elements 9-8 creating 9-9 decomposition sequence 14-151 definition 9-4 determining composition 14-193 subimage 3-22, 3-23, 14-357 subplot 3-22 subtraction of images 2-26, 9-44 of one image from another 1-13 sum 2-17, 14-369 surf viewing images 1-11 T template matching 8-14 texture mapping 3-28, 14-371 tform 14-296 tformarray 14-359 tformfwd 14-363 tforminv 14-364 thresholding to create a binary image 1-15, 14-162 to create indexed image from intensity image 14-153 TIFF 2-18, 14-215, 14-243, 14-271 bit depths supported when reading 14-247 bit depths supported when writing 14-275 compression 14-272 ImageDescription field 14-272 parameters that can be set when writing 14-272 reading with special imread syntax 14-244 resolution 14-272 writemode 14-272 tomography 8-27 transformation matrix 7-17 transforms 8-2 definition 8-3 discrete cosine 8-17, 14-89 discrete Fourier transform 8-9 Fourier 8-4, 14-116, 14-118, 14-119 inverse discrete cosine 14-159 inverse Fourier 14-160, 14-161 inverse Radon 8-27, 14-282 Radon 8-21, 14-325 two-dimensional Fourier transform 8-4 translate 14-365 transparency 13-5, 14-244 transparency chunk 14-244 troubleshooting for display 3-30 image displays 3-30 truecolor 13-7 truesize 3-26, 14-366 truncation rules for image arithmetic operators 2-24 typographical conventions (table) xxxi I-23 Index U bit depths supported when writing 14-275 uint16 14-369 storing images in 2-4, 2-18 supported operations for 14-369 uint8 14-367 storing images in 2-4, 2-18 supported operations for 14-367 uniform quantization See quantization unsharp filter 14-130 demo of xxxvi unsharp masking 7-14 W warp 3-28, 14-371 example 3-28 watershed 14-373 watershed example 9-47 watershed demo xxxv watershed segmentation example 9-42 Wiener filter deblurring with 12-6 demo xxxiv wiener2 10-24, 14-376 example 10-24 See also nrfiltdemo windowing method (filter design) 7-19, 14-138, 14-142 X X-ray absorption tomography 8-28 XWD 2-18, 14-215, 14-243, 14-271 bit depths supported when reading 14-247 I-24 Y YCbCr color space 13-17, 14-339, 14-378 ycbcr2rgb 13-17 YIQ 13-16 Z zero padding 8-13 and the fast Fourier transform 8-11 image boundaries 7-10 zero-cross edge detector 14-109 zero-frequency component zoom 3-27, 14-379 zooming Control Point Selection Tool 5-20 in figure window 3-26 zooming in 14-379 [...]... can use to implement morphological image processing operations • Chapter 10, “Analyzing and Enhancing Images” discusses working with image data and displaying images in MATLAB and the Image Processing Toolbox • Chapter 11, “Region-Based Processing describes how to perform image processing on specific regions of an image • Chapter 12, Image Deblurring” describes the toolbox deblurring functions • Chapter... the Image Processing Toolbox • Chapter 2, “Introduction” introduces the Image Processing Toolbox and its capabilities • Chapter 3, “Displaying and Printing Images” describes how to display and print images in MATLAB • Chapter 4, “Spatial Transformations” describes image cropping, resizing, rotating, and other geometric transformations you can perform with the Image Processing Toolbox • Chapter 5, Image. .. the Image Processing Toolbox? xii R12 Related Products List xiii Configuration Notes xv About This Manual xvi Words You Need to Know xvii Typographical Conventions xviii Image Processing Demos xx MATLAB Newsgroup xxiv Preface What Is the Image Processing Toolbox? The Image Processing Toolbox. .. M-files, a series of MATLAB statements that implement specialized image processing algorithms You can view the MATLAB code for these functions using the statement type function_name You can extend the capabilities of the Image Processing Toolbox by writing your own M-files, or by using the toolbox in combination with other toolboxes, such as the Signal Processing Toolbox and the Wavelet Toolbox For a list... xxxii Preface Image Processing Demos The Image Processing Toolbox is supported by a full complement of demo applications These are very useful as templates for your own end-user applications, or for seeing how to use and combine your toolbox functions for powerful image analysis and enhancement The toolbox demos are located under the subdirectory, matlabroot \toolbox\ images\imdemos where matlabroot represents... Description Signal Processing Toolbox Tool for algorithm development, signal and linear system analysis, and time-series data modeling Wavelet Toolbox Tool for signal and image analysis, compression, and de-noising Configuration Notes Configuration Notes To determine if the Image Processing Toolbox is installed on your system, type this command at the MATLAB prompt ver When you enter this command, MATLAB displays... the MATLAB numeric computing environment The toolbox supports a wide range of image processing operations, including: • Spatial image transformations • Morphological operations • Neighborhood and block operations • Linear filtering and filter design • Transforms • Image analysis and enhancement • Image registration • Deblurring • Region of interest operations Many of the toolbox functions are MATLAB. .. be interested in the MATLAB newsgroup (comp.soft-sys .matlab) This newsgroup gives you access to an active MATLAB user community It is an excellent way to seek advice and to share algorithms, sample code, and M-files with other MATLAB users xxxvii 1 Getting Started Overview 1-2 Exercise 1 — Some Basic Topics 1 Read and Display an Image 2 Check the Image in Memory ... in version 3.0, see the Release Notes xxv R12 Related Products List R12 Related Products List The Image Processing Toolbox requires MATLAB 6.0 (Release 12) Additionally, The MathWorks provides several products that are especially relevant to the kinds of tasks you can perform with the Image Processing Toolbox For more information about any of these products, see either: • The online documentation for... Note The toolboxes listed below all include functions that extend MATLAB s capabilities The blocksets all include blocks that extend Simulink’s capabilities Product Description DSP Blockset Simulink block libraries for the design, simulation, and prototyping of digital signal processing systems Mapping Toolbox Tool for analyzing and displaying geographically based information from within MATLAB MATLAB