代写QuadtreeBitmap程序、代作bitmap java、代写QuadtreeBitmap国外

日期：2018-07-24 08:53

Implement methods for a quadtree representation of bitmap

images.

Our representation of quadtrees will not have a separate Node

class. Instead, a QuadtreeBitmap itself can be thought of as a node.

A QuadtreeBitmap is either a leaf, in which case it represents a

square region of pixels all of the same colour; or an internal node, in

which case it has four child QuadtreeBitmaps, one per quadrant of

the bitmap image.

You may implement your submission in either Java or Python. The

only file which you need to edit is QuadtreeBitmap.java or

quadtree_bitmap.py, which contains a class QuadtreeBitmap, which

contains the methods you need to implement:

• blackenNorthWestQuadrant() : blacken the entire north-west

quadrant.

• countPixels(Colour) : count pixels of a given colour in the bitmap

represented by the quadtree.

• invertColours() : invert the colours in the bitmap represented by

the quadtree, i.e. turn every black pixel white and every white

pixel black.

• setPixel(int x, int y, Colour) : change the colour of a single pixel in

the bitmap represented by the quadtree, to the specified

colour.

• computeOverlay(QuadtreeBitmap bmp1, QuadtreeBitmap bmp2) :

construct and return the overlay of the two input images of the

same size. In the overlay a pixel is black if either of the input

images has a black pixel in the same location. That is, a pixel

in the output image is white only when the corresponding pixel

in both input images is white, otherwise the output pixel is

black. Rather than do the operation pixel by pixel, one can

compute the overlay more efficiently by leveraging the

quadtree's ability to represent multiple pixels with a single

node.

Note: for full marks, the resulting quadtree needs to be in "reduced"

form, i.e. any subtree that is entirely one colour needs to be

reduced to a single leaf.

Empty method definitions have been provided in the QuadtreeBitmap

class for each of the methods you need to implement. They start

from line 115 of the Java scaffold, and from line 90 of the Python

scaffold.

We have provided a scaffold which includes many helpful things,

such as:

• A method which constructs a QuadtreeBitmap from a string

representation. See below for details on the string

representation format expected.

• A method which converts a QuadtreeBitmap into a string

representation.

• Various constructors which you might find helpful, e.g.

◦ A constructor which creates a leaf QuadtreeBitmap for a

given location and size.

◦ A constructor which creates a QuadtreeBitmap for a given

location and size, with quadrants given by a list of

QuadtreeBitmaps provided as an argument.

• Convenience methods, e.g.

◦ A method which enumerates quadrants in the following

order: northeast, northwest, southeast, southwest.

◦ A method which determines which quadrant an input (x,

y) coordinate pair lies within. (If any.)

◦ A convenience method which you may enable, which

reads a string representation of a bitmap from standard

input and constructs the corresponding QuadtreeBitmap.

◦ Methods which generate string representations of a

QuadtreeBitmap, both as a string representation of the

bitmap it encodes, and with boxing interspersed to depict

its tree structure.

A main method, which will not be tested, has also been provided

and may be used by you for experimentation/testing: it's at line 178

of the Java scaffold and at the top of the Python scaffold. If you run

the scaffold code in its initial state, you will be asked to enter a

string representing a bitmap. Try entering the example from the

sheet:

Text

........

.....***

...***..

..**....

..*.....

.**...**

**...***

*....***

We advise against changing the other methods provided in the

scaffold. You are allowed to write additional methods, classes, etc.,

and add additional source files to your assignment workspace as

you see fit, though take note of the University's plagiarism policy.

Colour.java

LANGUAGE

QuadtreeBitmap.java

build.sh

core.py

quadtree_bitmap.py

run.sh