Common image processing functions

I. General functions:

 

 

 

 

 

Color Bar Display

 

 

 

Syntax: colorbar \ colorbar ('vert') \ colorbar ('horiz ') \ colorbar (h) \ h = colorbar (...) \ colorbar (..., 'peer ', axes_handle)

Getimage obtains image data from the coordinate axis

Syntax: A = getimage (h) \ [x, y, A] = getimage (h )\[..., a, flag] = getimage (h) \ [...] = getimage

Imshow display image

Syntax: imshow (I, n) \ imshow (I, [low high]) \ imshow (BW) \ imshow (X, map) \ imshow (RGB) \ imshow (..., display_option) \ imshow (x, y, ,...) \ imshow filename \ h = imshow (...)

Multiple images are displayed in the rectangle frame at the same time

Syntax: age (I) \ age (BW) \ age (X, map) \ age (RGB) \ h = age (...)

Create a multi-frame index graph movie animation using immovie

Syntax: mov = immovie (X, map) \ mov = immovie (RGB)

Subimage displays multiple images in one image

Syntax: subimage (X, map) \ subimage (I) \ subimage (BW) \ subimage (RGB) \ subimage (x, y ,...) \ subimage (...)

Truesize: adjust the image display size

Syntax: truesize (fig, [mrows mcols]) \ truesize (fig)

Warp displays the image on the texture ing surface

Syntax: warp (X, map) \ warp (I, n) \ warp (z ,...) warp (x, y, z ,...) \ h = warp (...)

Zoom image

Syntax: zoom on \ zoom off \ zoom out \ zoom reset \ zoom xon \ zoom yon \ zoom (factor) \ zoom (fig, option)

II. Image file I/O function commands

Imfinfo returns image file information

Syntax: info = imfinfo (filename, fmt) \ info = imfinfo (filename)

Imread reads (loads) images from image files

Syntax: A = imread (filename, fmt) \ [X, map] = imread (filename, fmt) \ [...] = imread (filename) \ [...] = imread (URL ,...) \ [...] = imread (..., idx) (CUR, ICO, and TIFF only) \ [...] = imread (..., 'frames ', idx) (GIF only) \ [...] = imread (..., ref) (HDF only) \ [...] = imread (..., 'backgroundcolor', BG) (PNG only) \ [A, map, alpha] = imread (...) (ICO, CUR, PNG only)

Imwrite writes (save) an image file

Syntax: imwrite (A, filename, fmt) \ imwrite (X, map, filename, fmt) \ imwrite (..., filename) \ imwite (..., param1, Val1, Param2, Val2 ...)

Imcdrop cut Image

Syntax: I2 = imcdrop (I) \ X2 = imcdrop (X, map) \ RGB2 = imcdrop (RGB) \ I2 = imcdrop (I, rect) \ X2 = imcdrop (RGB, rect) \ [...] = imcdrop (x, y ,...) \ [A, rect] = imcrop (...) \ [x, y, A, rect] = imcdrop (...)

Imresize changes Image size

Syntax: B = imresize (A, m, method)

Imrotate rotating image

Syntax: B = imrotate (A, angle, method) \ B = imrotate (A, angle, method, 'crop ')

3. Pixel and statistical processing functions

Corr2 calculates the two-dimensional correlation coefficient of two rectangles.

Syntax: r = corr2 (A, B)

Imcontour

Syntax: imcontour (I, n) \ imcontour (I, v) \ imcontour (x, y ,...) \ imcontour (..., lineSpec) \ [C, h] = imcontour (...)

Use imfeature to calculate the feature size of the image area

Syntax: stats = imfeature (L, measurements) \ stats = imfeature (L, measurements, n)

Imbist displays the column chart of image data

Impixel determines the pixel color value

Syntax: P = impixel (I) \ P = impixel (X, map) \ P = impixel (RGB) \ P = impixel (I, c, r) \ P = impixel (X, map, c, r) \ P = impixel (RGB, c, r) \ [c, r, P] = impixel (...) \ P = impixel (x, y, I, xi, yi) \ P = impixel (x, y, RGB, xi, yi) \ P = impixel (x, y, y, x, map, xi, yi )\

[Xi, yi, P] = impixel (x, y ,...)
Calculate the pixel value of the profile along the improfile line

Syntax: c = improfile \ c = improfile (n) \ c = improfile (I, xi, yi) \ c = improfile (I, xi, yi, n) \ [cx, cy, c] = improfile (...) \ [cx, cy, c, xi, yi] = improfile (...) \ [...] = improfile (x, y, I, xi, yi) \ [...] = improfile (x, y, I, xi, yi, n) \ [...] = improfile (..., method)

Mean2 calculates the average value of matrix elements

Syntax: B = mean2 ()

Pixval: displays the pixel information of an image.

Syntax: pixval on

Std2 calculates the standard offset of matrix elements

Syntax: B = std2 ()

IV. Image analysis functions:

Edge Image edge detection

Syntax: BW = edge (I, 'job') \ BW = edge (I, 'job', thresh) \ BW = edge (I, 'job', thresh, direction) \ [BW, thresh] = edge (I, 'sobel ',...) \ BW = edge (I, 'prewitht') \ BW = edge (I, 'prewitht', thresh) \ BW = edge (I, 'prewitht', thresh, direction )\

[BW, thresh] = edge (I, 'prewitt ',...) \ BW = edge (I, 'ots') \ BW = edge (I, 'ots', thresh) \ [BW, thresh] = edge (I, 'ots ',...) \ BW = edge (I, 'log') \ BW = edge (I, 'log', thresh) \ BW = edge (I, 'log', thresh, sigma) \ [BW, threshold] = edge (I, 'log ',...) \ BW = edge (I, 'zeroscross ', thresh, h) \ [BW, thresh] = edge (I, 'zeroscross ',...) \

BW = edge (I, 'hangzhou') \ BW = edge (I, 'hangzhou', thresh) \ BW = edge (I, 'hangzhou', thresh, sigma) \ [BW, threshold] = edge (I, 'ecoly ',...)

Qtgetblk gets the block value of the quad-tree decomposition.

Syntax: [vals, r, c] = qtgetblk (I, S, dim) \ [vals, idx] = qtgetblk (I, S, dim)

Qtsetblk

Syntax: J = qtsetblk (I, S, dim, vals)

V. Image enhancement functions

Enhanced Comparison of histeq histogram equalization

Syntax: J = histeq (I, hgram) \ J = histeq (I, n) \ [J, T] = histeq (I ,...) \ newmap = histeq (X, map, hgram) \ newmap = histeq (X, map)

Imadjust: adjust the gray scale or color image table of the image

Syntax: J = imadjust (I, [low_in, high_in]), [low_out, high_out], gamma) \ newmap = imadjust (map, [low_in, high_in]), [low_out, high_out], gamma) \ RGB2 = imadjust (RGB1 ,...)

Imnoise enhances image rendering

Syntax: J = imnoise (I, type) \ J = imnoise (I, type, parameters)

Medfilt2 performs two-dimensional median filtering

Syntax: B = medfilt2 (A, [m n]) \ B = medfilt2 (A) \ B = medfilt2 (A, 'indexed ',...)

Ordfilt2 performs two-dimensional statistical sequence filtering

Syntax: B = ordfilt2 (A, order, domain) \ B = ordfilt2 (A, order, domain, S) \ B = ordfilt2 (..., padopt)

Wiener2 for two-dimensional adaptive denoising filtering

Syntax: J = wiener2 (I, [m n], noise) \ [J, noise] = wiener2 (I, [m n])

VI. Linear filtering functions

Conv2 performs two-dimensional convolution

Syntax: C = conv2 (A, B) \ C = conv2 (hcol, hrow, A) \ C = conv2 (..., 'shape ')

Convmtx2 computing two-dimensional convolution matrix

Syntax: T = convmtx2 (H, m, n) \ T = convmtx2 (H, [m n])

Convn calculates n-dimensional convolution

Syntax: C = convn (A, B) \ C = convn (A, B, 'shape ')

Filter2 for two-dimensional linear filtering

Syntax: Y = filter2 (h, X) \ Y = filter2 (h, X, shape)

Fspecial create predefine filter

Syntax: h = fspecial (type) \ h = fspecial (type, parameters)

VII. Linear two-dimensional filtering design functions

Freqspace: determine the frequency space of two-dimensional frequency response

Syntax: [f1, f2] = freqspace (n) \ [f1, f2] = freqspace ([m n]) \ [x1, y1] = freqspace (..., 'meshgrid') \ f = freqspace (N, 'whole ')

Freqz2 calculates two-dimensional frequency response

Syntax: [H, f1, f2] = freqz2 (h, n1, n2) \ [H, fi, f2] = freqz2 (h, [n2, n1]) \ [H, fi, f2] = freqz2 (h, f1, f2]) \ [H, fi, f2] = freqz2 (h) \ [...] = freqz2 (h ,..., [dx dy]) \ [...] = freqz2 (h ,..., dx) \ freqz2 (...)

Design of two-dimensional FIR filter using frequency sampling method in fsamp2

Syntax: h = fsamp2 (Hd) \ h = fsamp2 (f1, f2, Hd, [m n])

Ftrans2 designs two-dimensional FIR filter based on frequency conversion

Syntax: h = ftrans2 (B, t) \ h = ftrans2 (B)

Design of two-dimensional FIR filter using one-dimensional window method in fwind1

Syntax: h = fwind1 (Hd, win) \ h = fwind1 (Hd, win1, win2) \ h = fwind1 (f1, f2, Hd ,...)

Design of two-dimensional FIR filter using two-dimensional window method in fwind2

Syntax: h = fwind2 (Hd, win) \ h = fwind2 (f1, f2, Hd, win)

8. Image transformation functions

Dct2 implements two-dimensional discrete cosine transformation (idct2 for inverse cosine transformation)

Syntax: B = dct2 (A) \ B = dct2 (A, m. n) \ B = dct2 (A, [m n])

Calculation of discrete cosine Fourier transformation using dctctx

Syntax: D = dctctx (n)

Fft2 performs two-dimensional fast Fourier transformation (ifft2 is used for inverse transformation)

Syntax: Y = fft2 (X) \ Y = fft2 (X, m, n)

Fftn performs n-dimensional fast Fourier transformation (ifftn for inverse transformation)

Syntax: Y = ffn (X) \ Y = fftn (X, siz)

The DC component of fftshift fast Fourier transformation is moved to the spectral center.

Syntax: Y = fftshift (X) \ Y = fftshift (X, dim)

Iradon for anti-Euclidean transformation

Syntax: I = iradon (P, theta) \ I = iradon (P, theta, interp, filter, d, n) \ [I, h] = iradon (...)

Phantom generates a phantom image of the head

Syntax: P = phantom (def, n) \ P = phantom (E, n) \ [P, E] = phantom (...)

Calculation of the euclidean transform using the Euclidean algorithm

Syntax: R = registers (I, theta) \ [R, xp] = records (...)

9. Edge and block processing functions

Bestblk determines the block size for block operations

Syntax: siz = bestblk ([m n], k) \ [mb, nb] = bestblk ([m n], k)

Blkproc implements Image Display block operations

Syntax: B = blkproc (A, [m n]), fun) \ B = blkproc (A, [m n], fun, P1, P2 ,...) \ B = blkproc (A, [m n], [mborder nborder], fun ,...)

Col2im re-organizes columns in the matrix into blocks.

Syntax: A = col2im (B, [m n], [mm nn], block_type) \ A = col2im (B, [m n], [mm nn])

Colfilt uses column-related functions for edge operations

Syntax: B = colfilt (A, [m n], block_type, fun) \ B = colfilt (A, [m n], block_type, fun, P1, p2 ,...) \ B = colfilt (A, [m n], [mblock nblock],...) \ B = colfilt (A, 'indexed ',...)

Im2col re-tune the image block as a column

Syntax: B = im2col (A, [m n], block_type) \ B = im2col (A, [m n]) \ B = im2col (, 'indexed ',...)

Edge operation by nlfilter

Syntax: B = nlfilter (A, [m n], fun) \ B = nlfilter (A, [m n], fun, P1, P2 ,...) \ B = nlfilter (A, 'indexed ',...)

10. Binary image operation functions

Use the lookup table in the binary image to perform row edge operations.

Syntax: A = applylut (BW, LUT)

Bwarea calculates the area of the binary image object

Syntax: total = bwarea (BW)

Bwe calculates the number of operating records of binary images.

Syntax: eul = bwe.pdf (BW)

Bwfill fills in the background color of the binary image

Syntax: BW2 = bwfill (BW1, c, r, n) \ BW2 = bwfill (BW1, n) \ [BW2, idx] = bwfill (...) \ BW2 = bwfill (x, y, BW1, xi, yi, n) \ [x, y, BW2, idx, xi, yi] = bwfill (...) \ [BW2, idx] = bwfill (BW1, 'holes ', n)

Bwlabel indicates the connected part of the binary image

Syntax: L = bwlabel (BW, n) \ [L, num] = bwlabel (BW, n)

Bwmorph extract the contour of binary images

Syntax: BW2 = bwmorph (BW1, operation) \ BW2 = bwmorph (BW1, operation, n)

Bwperim calculates the perimeter of an object in a binary image

Syntax: BW2 = bwperim (BW1) \ BW2 = bwperim (BW1, CONN)

Bwselect select an object in a binary image

Syntax: BW2 = bwselect (BW1, c, r, n) \ BW2 = bwselect (BW1, n) \ [BW2, idx] = bwselect (...) \ BW2 = bwselect (x, y, BW1, xi, yi, n) \ [x, y, BW2, idx, xi, yi] = bwselect (...)

Dilate to enlarge the binary image

Syntax: BW2 = dilate (BW1, SE) \ BW2 = dilate (BW1, SE, alg) \ BW2 = dilate (BW1, SE,..., n)

Erode weakens the boundaries of binary images

Syntax: BW2 = erode (BW1, SE) \ BW2 = erode (BW1, SE, alg) \ BW2 = erode (BW1, SE,..., n)

Makelut creates a lookup table for the applylut function.

Syntax: lut = makelut (fun, n) \ lut = makelut (fun, n, P1, P2 ,...)

11. Regional processing functions

Roicolor select the color area of interest

Syntax: BW = roicolor (A, low, high) \ BW = rocicolor (A, v)

Roabaqus performs smooth interpolation in any area of the image

Syntax: J = roabaqus (I, c, r) \ J = roabaqus (I, BW) \ [J, BW] = roabaqus (...) \ J = roabaqus (x, y, I, xi, yi) \ [x, y, J, BW, xi, yi] = roabaqus (...)

Roifilt2 filter sensitive areas

Syntax: J = roifilt2 (h, I, BW) \ J = roifilt2 (I, BW, fun) \ J = roifilt2 (I, BW, fun, P1, p2 ,...)

Roipoly selects a sensitive polygon area

Syntax: BW = roipoly (I, c, r) \ BW = roipoly (I) \ BW = roipoly (x, y, I, xi, yi) \ [BW, xi, yi] = roipoly (...) \ [x, y, BW, xi, yi] = roipoly (...)

12. Color image processing functions

Brighten increase or decrease the brightness of the color image table

Syntax: brighten (beta) \ brighten (h, beta) \ newmap = brighten (cmap, beta)

Cmpermute: adjust the color in the color image table

Syntax: [Y, newmap] = cmpermute (X, map) \ [Y, newmap] = cmpermute (X, map, index)

Cmunigue searches for specific colors and corresponding images in the color image table.

Syntax: [Y, newmap] = cmunigue (X, map) \ [Y, newmap] = cmunigue (RGB) \ [Y, newmap] = cmunique (I)

Imapprox performs approximate processing on indexed images

Syntax: [Y, newmap] = imapprox (X, map, n) \ [Y, newmap] = imapprox (X, map, tol) \ Y = imapprox (X, map, newmap) \ [...] = imapprox (..., dither_option)

Rgbplot division color image table

Syntax: rgbplot (cmap)

13. Color space conversion function

HSV 2rgb converted to RGB color space: M = HSV 2rgb (H)

Ntsc2rgb conversion NTSC value is RGB color space: rgbmap = ntsc2rgb (yiqmap) \ RGB = ntsc2rgb (YIQ)

Rgb2hsv converts RGB values to HSV color space: cmap = rgb2hsv (M)

The RGB value of rgb2ntsc is NTSC color space: yiqmap = rgb2ntsc (rgbmap) \ YIQ = rgb2ntsc (RGB)

Rgb2ycbcr converts RGB values to YCbCr color space: ycbcrmap = rgb2ycbcr (rgbmap) \ YCBCR = rgb2ycbcr (RGB)

Ycbcr2rgb convert YCbCr value to RGB color space: rgbmap = ycbcr2rgb (ycbcrmap) \ RGB = ycbcr2rgb (YCBCR)

IV. Image types and type conversion functions

Dither uses jitter to increase the appearance color resolution to convert the image

Syntax: X = dither (RGB, map) \ BW = dither (I)

Gray2ind converts grayscale images to indexed images

Syntax: [X, map] = gray2ind (I, n) \ [X, map] = gray2ind (BW, n)

Grayslice uses grayscale images as index images

Syntax: X = grayslice (I, n) \ X = grayslice (I, v)

Convert im2bw image to binary image

Syntax: BW = im2bw (I, level) \ BW = im2bw (X, map, level) \ BW = im2bw (RGB, level)

Im2double conversion Image matrix is double precision type

Syntax: I2 = im2double (I1) \ RGB2 = im2double (RGB1) \ I = im2double (BW) \ X2 = im2double (X1, 'indexed ')

Convert double to double

Syntax: double (X)

Unit8 and unit16 convert data to 8-bit and 16-bit unsigned integer: I = unit8 (x) \ I = unit16 (x)

Im2unit8 converts an image array to an 8-bit unsigned integer

Syntax: I2 = im2unit8 (I1) \ RGB2 = im2unit8 (RGB1) \ I = im2unit8 (BW) \ X2 = im2unit8 (X1, 'indexed ')

Im2unit16 converts the image array to a 16-bit unsigned integer

Syntax: I2 = im2unit16 (I1) \ RGB2 = im2unit16 (RGB1) \ I = im2unit16 (BW) \ X2 = im2unit16 (X1, 'indexed ')

Ind2gray converts the retrieved image to a grayscale image

Syntax: I = ind2gray (X, map)

Ind2rgb convert index image to RGB true color image

Syntax: RGB = ind2rgb (X, map)

Isbw determines whether the image is a binary image

Syntax: flag = isbw ()

Isgray determines whether a gray image is used

Syntax: flag = isgray ()

Isind determines whether the image is indexed

Syntax: flag = isind ()

Isrgb determines if it is an RGB true color image

Syntax: flag = isrgb ()

The mat2gray conversion matrix is a grayscale image.

Syntax: I = mat2gray (A, [amin amax]) \ I = mat2gray ()

Rgb2gray converts RGB images or color image tables to grayscale images

Syntax: I = rgb2gray (RGB) \ newmap = rgb2gray (map)

Rgb2ind converts RGB images to indexed images

Syntax: [X, map] = rgb2ind (RGB, tol) \ [X, map] = rgb2ind (RGB, n) \ X = rgb2ind (RGB, map) \ [...] = rgb2ind (..., dither_option)

15. Added the image processing toolbox function.

Adapthisteq restricted contrast histogram equalization: J = adapthisteq (I) \ J = adapthisteq (I, param1, val1, param2, val2 ...)

Applycform is used for color space transformation out = applyform (I, C)

Bwboundaries depicts binary image boundaries

Syntax: B = bwboundaries (BW) \ B = bwboundaries (BW, CONN) \ B = bwboundaries (BW, CONN, options) [BW, CONN, options] \ [BL] = bwboundaries (...) \ [BLNA] = bwboundaries ()

Bwtraceboundary describes objects in binary images

B = bwtraceboundary (BW, P, fstep) \ B = bwtraceboundary (BW, P, fstep, CONN) \ B = bwtraceboundary (... N, dir)

Demo-strech de-correlation processing for multi-channel images

Syntax: S = demo-stretch (I) \ S = demo-stretch (I, TOL)

Dicomdict: obtain or read DICOM files

Syntax: dicomdict ('set', dictionary) \ dictionary = dicomdict ('get ')

Getline select ployline with the mouse

 

Syntax: [x, y] = getline (fig) \ [x, y] = getline (ax) \ [x, y] = getline \ [x, y] = getline (..., 'closed ')

 

Getpts selects the pixel with the mouse

Syntax: [x, y] = getpts (fig) \ [x, y] = getpts (ax) \ [x, y] = getpts

Getrect select the matrix with the mouse

Syntax: rect = getrect (fig) \ rect = getrect (ax) \ rect = getrect (fig)

Iccread read ICC profile

Syntax: P = iccread (filename)

Im2java2d converts an image into a Java buffer image

Syntax: jimage = im2java2d (I) \ jimage = im2java2d (X, MAP)

Imview displays images in the image and blue flag

Syntax: imview (I) \ imview (RGB) \ imview (X, map) \ imview (I, range) \ imview (filename) \ imview (.... 'initialmagnification', initial_mag) \ h = imview (...) \ imview close all

Ippl check IPPL

Syntax: TF = ippl \ [tf B] = ippl

Index image in iptdemos Display Image Processing Toolbox

Lab2double, lab2unit16, and lab2unit8 convert L * a * B data into dual-precision, 16-bit data, and 8-bit data respectively.

Makecform creates a color conversion structure

Poly2mask converts a polygon area to a mask area.

Syntax: BW = poly2mask (x, y, m, n)

Unitlut

Syntax: B = unitlut (A, LUT)

Xyz2double and xyz2unit16 convert color data from XYZ to dual precision and hexadecimal.

 

 

 

 

 

 

 

 

Syntax: xyzd = xyz2double (XYZ) \ xyz16 = xyz2unit16 (xyz)

Common image processing functions