#ifndef $\_\_$ANSWER$04\_$H$\_\_$

#define $\_\_$ANSWER$04\_$H$\_\_$

#include

#include

#include

#pragma pack$($push$)//$ save the original data alignment

#pragma pack$(1)//$ Set data alignment to $1$ byte boundary

$/*$

$*$ BMP files are laid out in the following fashion:

$*--------------------------$

$*|$Header $|54$ bytes

$*|-------------------------$

$*|$ Image Data $|$ file size $-54($for $24-$bit images$)$

$*--------------------------$

$*/$

$/**$

$*$ BMP header $(54$ bytes$).$

$*$ uint$16\_$t is $16-$bit unsigned integer

$*$ uint$32\_$t is $32-$bit unsigned integer

$*$ int$32\_$t is $32-$bit signed integer

$*/$

typedef struct $\_$BMP$\_$header $\{$

$$ uint$16\_$t type; $//$ Magic identifier

$$ uint$32\_$t size; $//$ File size in bytes

$$ uint$16\_$t reserved$1$; $//$ Not used

$$ uint$16\_$t reserved$2$; $//$ Not used

$$ uint$32\_$t offset; $//$ Offset to image data in bytes from

$//$ beginning of file $(54$ bytes$)$

$$ uint$32\_$t DIB$\_$header$\_$size; $//$ DIB header size in bytes $(40$ bytes$)$

$$ int$32\_$t $$width; $//$ Width of the image

$$ int$32\_$t $$height; $//$ Height of image

$$ uint$16\_$t planes; $//$ Number of color planes

$$ uint$16\_$t bits; $//$ Bits per pixel

$$ uint$32\_$t compression; $//$ Compression type

$$ uint$32\_$t imagesize; $//$ Image size in bytes

$$ int$32\_$t $$xresolution; $//$ Pixels per meter

$$ int$32\_$t $$yresolution; $//$ Pixels per meter

$$ uint$32\_$t ncolours; $//$ Number of colors $$

$$ uint$32\_$t importantcolours; $//$ Important colors

$\}$ BMP$\_$header;

#pragma pack$($pop$)//$ restore the previous pack setting

typedef struct $\_$BMP$\_$image $\{$

$$ BMP$\_$header header;

$$ unsigned char $*$data;

$\}$ BMP$\_$image;

$//$ Given a BMP$\_$image, create a new $16-$bit image that is converted from a given $//24-$bit image $//$ BMP$\_$image $*$convert$\_24\_$to$\_16\_$BMP$\_$image$($BMP$\_$image $*$image$)$; For the given image, you may assume that it is a valid $24-$bit image; otherwise, this function should not be called at all. You have to take the $24-$bit representation and convert it into a $16-$bit representation. Note that you should not modify the original image. Instead, the function should allocate new memory spaces to store the new header information and the new image data. The header information of the new image should not be identical to that of the original image. In particular, you would have to compute the number of bytes in each row and the total image size, and therefore the file size. You have to downscale $8$ bits to $5$ bits for each color. You have to scale $0$ through $255$ to $0$ through $31.$ A division of a color value by $8$ or a right shift of $3$ position should achieve similar outcome because you are ECE$26400$ Purdue University $3$ c Cheng$-$Kok Koh dealing with non$-$negative numbers. You also have to combine the three colors into two bytes $($using perhaps bit$-$wise OR operation$).$ Lastly, you have to store the two bytes into the data array of the new BMP image. It is important that the padding bytes, if required, are all assigned $0.$