Script Builtin Apis

Basic Image Apis

imread

function imread(ImageName) {}

reads in image according to ImageName, returns the image object

param	type	description	note
ImageName	string	the path of the image desired to read	-
RETURN	Image	the image read	-

Sample Usage

im = imread("moon.png")

imwrite

function imread(ImageName, Image) {}

reads in image according to ImageName, returns the image object

param	type	description	note
ImageName	string	the path of the image desired to write	-
Image	Image	the image object	-
RETURN	-	no returns	-

Sample Usage

im = imread("moon.png")
imwrite("moon_copy.png")

fspecial

function fspecial(Filter, ...) {}

reads in image according to ImageName, returns the image object

param	type	description	note
Filter	string	string that name sepcifies the filter	See Filters Names
RETURN	pod	plain old pointer	-

Filter Name	Params Required	Description
"laplacian"	-	laplacian operator,
"gaussian"	[array] - specifies the size of the filter [double] - specifies sigma	-
"average"	[array] - specifies the size of the filter	-

Sample Usage

filter_size = [3, 3]
lap = fspecial("laplacian")
avg = fspecial("average", filter_size)
gau = fspecial("gaussian", [15, 15], 3.0)

imfilter

function imfilter(Image, Filter, Filter_Size)
function imfilter(Config)

param	type	description	Default	note
Image	Image	The Image To be filtered	-
Filter	pod	filter generated by fspecial	-
Filter_Size	array	size of the filter	[3, 3]
RETURN	Image	Image after filtering	x

Another Usage

param	type	description	Default	note
Config	object	Object specifies options	-	See Config Options
RETURN	Image	Image after filtering	x

Config Options	type	default	note
filter	pod	-	filter generated by fspecial()
filter_size	array	[3,3]	filter size
filter_factor	double	1	All element of filter will multiple the filter
src	Image	-	Source Image
bounds	array or object	[[0,0],[1,1]]	See description below

• Bounds specifies which part of the image will be filtered.

  • It can be an array of 2 coordinate, first specifies the left bottom and second specifies right top

  • It can be an object specifies left, right, top, and bottom position from the origin

Sample Usage

filter_size = [3, 3]
im = imread("gorilla.jpg")

average = imfilter(im, fspecial("average", filter_size), filter_size)
config = {
    filter_size : [15, 15],
    filter_factor: 1.3, //every elem of filter will multiply the factor
    filter : fspecial("gaussian", [15, 15], 3.0),
    src : im,
    bounds : [[0, 0], [.5, .5]]
}
imwrite("gorilla_gaus_quater.png", imfilter(config))