Pixel-Image

A single plane of image data is represented by pixel-image object. pixel-image is a two-dimensional array of bytes. The interpretation of each byte is application dependent. Although it is most commonly used to represent brightness of a pixel, it may be used to represent edge intensity, gradient direction, color component intensity, bar graph, or whatever.

pixel-image [class]

  :super   array 

  :slots 		 xpicture display-lut histogram


brightness-distribution0


brightness-distribution1


brightness-covariance 

Pixel-image is the two dimensional array with displaying facility in xwindows. The pixel conversion is performed by display-lut and the resulted image is stored in xpicture. Major axis is taken vertically. The pixel of img at (x, y) should be accessed by (aref img y x).

:width [method]

returns the horizontal size of a pixel-image, which is the second dimension.

:height [method]

returns the vertical size of a pixel-image.

:size [method]

is equivalent to array-total-size.

:transpose &optional (result (instance (class self) :init dim0 dim1)) [method]

exchanges x and y coordinates.

:map-picture lut &optional (result (send self :duplicate)) [method]

This pixel-image is translated by the lut and stored in result.

:map fn &optional (result (send self :duplicate)) [method]

applies function fn to all the pixels in the image, and put the result in the result pixel-image.

:brightest-pixel [method]

finds the brightest pixel value in this image.

:darkest-pixel [method]

finds the darkest pixel value in this image.

:average-pixel [method]

calculates the average intensity of all the pixels in this image.

:halve &optional simage [method]

returns pixel-image that is shrunk into half-size image.

:subimage x y subwidth subheight [method]

cuts out a subwidth x subheight rectangular region with its top-left corner at (x,y) of this image. The origin of the image is taken at the top-left corner. :Subimage returns a new pixel-image object.

:xpicture &optional lut [method]

translates this image using the look-up table lut and sets translated pixel-image object to xpicture.

:display-lut &optional newlut [method]

sets look-up table newlut as display-lut.Then translates this image using this look-up table and sets translated pixel-image object as xpicture.

:display (xwin geometry:*viewsurface*) [method]

displays this pixel-image in the xwin xwindow by using :putimage. Each pixel value is referred as a index in x's color map. To get a desired appearance, this pixel-image must have been translated by proper LUTs.

:duplicate [method]

makes an instance of the same class as this image object with the same width and height. The pixel data are not copied.

:copy-from src [method]

copies pixel data from another image object specified by src. src must be of the same dimension as this image.

:hex &optional (x 0) (y 0) (w 16) (h 16) (strm t) [method]

prints pixel data in the specified rectangular region in the hexadecimal format.

:hex1 &optional (x 0) (y 0) (w 64) (h 16) (strm t) [method]

prints pixel data in the specified rectangular region in the hexadecimal format.

:grin1 strm &rest msg [method]

prints this image-pixel object with its name and dimensions.

:init w h &optional imgvec [method]

initializes a pixel-image object to have w width and h height.

:amplify rate &optional (result (send self :duplicate) [method]

multiplies rate to each pixel value.

:compress-gray-scale levels &optional result &aux pict2 [method]

translates this image into range of 0..levels and returns translated pixel-image object.

:lut lut1 &optional (result (send self :duplicate)) [method]

translates this image using the look-up table lut1 and returns translated pixel-image object.

:lut2 lut1 lut2 &optional (result (send self :duplicate)) [method]

translates this image using a look-up table that concatenated lut1 and lut1. And returns translated pixel-image object.

:histogram [method]

counts the occurrence of each pixel value in this image and returns an integer-vector representing the histogram.

:brightness-distribution [method]

returns brightness-distribution.

:optimum-threshold [method]

returns levels that is maximum of this image's brightness-distribution.

:project-x [method]

adds all pixel values of the same x coordinate and returns a vector of these values.

:project-y [method]

adds all pixel values of the same y coordinate and returns a vector of these values.

:digitize threshold &optional (val0 0) (val1 255) result [method]

translates this image into 2 levels image val0 and val1 using threshold.

:and img2 [method]

bit-and operates between this image and img2, and returns operated pixel-image.

:plot min max &optional color viewsurface [method]

plots pixels having values between min and max inclusively with color (gc) on viewsurface.

detects edge of this image. And displays this edge on this image.