Image_bln contains a Matrix_bln object, along with some additional spatial information.  Its main purpose is to make possible a matrix able to be placed in a 2 dimensional space.  Map projection information is also added to handle various types of Geographic information data.

Spatial information is automatically taken care of in all kind of Image object operations and functions, hence the user does not have to worry about it.

An image_bln object has a full access to all class functions of matrix, as well as its own class functions. 

Member data

Name Data type Meaning
id int ID of an image
matrix Matrix_bln a Matrix_bln object
lower_left Pt2D coordinate of lower left corner of an image
upper_right Pt2D coordinate of upper right corner of an image
projection Projection map projection of an image



See details in operator section.


Construction function

{Image_bln} ret  =  IMAGE_BLN([{int} argm1, {int} argm2, {double} argm3, {double} argm4, {double} argm5, {double} argm6, {Projection} argm7])

argm1 = no of row                      (default = 0)

argm2 = no of column                   (default = 0)

argm3 = x coordinate (lower left)      (default = 0)

argm4 = y coordinate (lower left)      (default = 0)

argm5 = x coordinate (upper right)     (default = 0)

argm6 = y coordinate (upper right)     (default = 0)

argm7 = map projection                 (default = default of Projection())


->Img = Image_bln() an empty image

->Img = Image_bln(100,200)



an image with 100 rows and 200 columns,

lewer left = (0,0) upper right = (200,100)

Projection = default value of function Projection()



object({int} argm1, {int} argm2)   =  {bool} left-value

argm1 = row index

argm2 = column index     

object.ID()          =  {int} left-value

object.LOWER_LEFT()  =  {Pt2D} left-value

object.UPPER_RIGHT(){Pt2D} left-value

object.MATRIX()      =  {Matrix} left-value

object.PROJ()        =  {Projection} left-value

object.FLAG_NULL()   =  {bool} left-value

object.NULLDATA()    =  {double} left-value


->Img(10,20) = 999 set value of element at row 10, column 20
->Img.lower_left() = Pt2D(10,200) set lower left point coordinate
->Img.upper_right() = Pt2D(100.536 ,2000.500) set upper right point coordinate
->P = Projection()


->Img.projection() = P

set a particular map projection
->A = [ 1 2 3; 4 5 6; 7 8 9]

->Img.matrix() = A 


change content of matrix to matrix "A"

Notice that coordinates of the two corner points remain the same, while size of Img changes to 3 rows and 3 columns, according to the size of "A" 


Class function

See class function of Image