BMP image flip

// BMP. h

# Ifndef _ BMP _h _
# DEFINE _ BMP _h _
# Pragma pack (1)

Typedef struct tagbitmapfileheader
{
Char bftype [2]; // file type, which is BM in Windows
Long bfsize; // File Size
Short bfreserved1; // reserved, set to 0
Short bfreserved2; // reserved, set to 0
Long bfoffbits; // offset of the actual graph data
} Bitmapfileheader;

Typedef struct tagbitmapinfoheader
{
Long bisize; // The number of bytes required by the Bitmap header. The value is 40 bytes in the windws system.
Long biwidth; // Image Width
Long biheight; // Image Height
Short biplanes; // specifies the number of bits for the target device. The value is 1.
Short bibitcount; // The number of digits occupied by each pixel. The color of 1-16 is 4,256, and the color of 8-24 is 24.
Long bicompression; // compression type, BMP is 0
Long bisizeimage; // image size, no compression set to 0
Long bixpelspermeter; // horizontal resolution
Long biypelspermeter; // vertical resolution
Long biclrused; // The number of colors used by the bitmap.
Long biclrimportant; // number of important colors
} Bitmapinfoheader;

Typedef struct tagrgbquad
{
Unsigned char rgbblue; // specify the blue intensity
Unsigned char rgbgreen; // specify the green intensity
Unsigned char rgbred; // specify the red intensity
Unsigned char rgbreserved; // reserved, set to 0
} Rgbquad;

 

Extern unsigned char * pbmpbuf; // pointer for reading image data
Extern long BMP width; // Image Width
Extern long bmpheight; // Image Height
Extern rgbquad * pcolortable; // color table pointer
Extern int bibitcount; // image type, number of digits per pixel
Extern int linebyte;
Extern bool readbmp (char *);
Extern bool savebmp (char *, unsigned char *, Int, rgbquad *);

# Endif

 

// Read. c

# Include <stdio. h>
# Include "BMP. H"
Bool readbmp (char * BMP name)
{// Open the specified image file in binary read mode
File * fp = fopen (BMP name, "rb ");
If (FP = 0) return 0;
// Define the bitmap file header structure variable, read the bitmap file header into the memory, and store it in the variable File
Bitmapfileheader file;
Fseek (FP, 0, 0 );
Fread (& file, sizeof (bitmapfileheader), 1, FP );
Printf ("%. 2 s", file. bftype );
Long bfsize = file. bfsize;
Short bfreserved1 = file. bfreserved1;
Short bfreserved2 = file. bfreserved2;
Long bfoffbits = file. bfoffbits;
// Define the bitmap information header structure variable, read the bitmap information header into the memory, and store it in the variable head
Bitmapinfoheader head;
Fread (& head, sizeof (bitmapinfoheader), 1, FP );
BMP width = head. biwidth;
Bmpheight = head. biheight;
Bibitcount = head. bibitcount;
// Define the variable to calculate the number of bytes occupied by each pixel in the image
Linebyte = (BMP width * bibitcount/8 + 3)/4*4;
// Grayscale images have a color table, and the color table item is 256
If (bibitcount = 8)
{// Apply for the space required by the color table. Read the color table into the memory.
Pcolortable = new rgbquad [256];
Fread (pcolortable, sizeof (rgbquad), 256, FP );
}
// The space required to apply for bitmap data. Read bitmap data into the memory.
Pbmpbuf = new unsigned char [linebyte * bmpheight];
Fread (pbmpbuf, 1, linebyte * bmpheight, FP );
// Close the file
Fclose (FP );
Return 1;
}

 

// Save. c

# Include <stdio. h>
# Include "BMP. H"
Bool savebmp (char * BMP name, unsigned char * imgbuf, int width, int height, int bibitcount,
Rgbquad * pcolortable)
{
// If the bitmap data pointer is 0, no data is passed in and the function returns
If (! Imgbuf)
Return 0;
// The color table size, in bytes. The gray scale image color table is 1024 bytes, and the color image color table size is 0.
Int colortablesize = 0;
If (bibitcount = 8)
Colortablesize = 1024;
// The number of bytes in each row of the image data to be stored is a multiple of 4.
Int linebyte = (width * bibitcount/8 + 3)/4*4;
// Open the file in binary mode
File * fp = fopen (BMP name, "WB + ");
If (FP = 0) return 0;
// Apply for bitmap file header Structure Variables and fill in the file header information
Bitmapfileheader file;
File. bftype [0] = 0x42; // BMP Type
File. bftype [1] = 0x4d;
// Bfsize is the sum of the four components of an image file.
File. bfsize = sizeof (bitmapfileheader) + sizeof (bitmapinfoheader)
+ Colortablesize + linebyte * height;
File. bfreserved1 = 0;
File. bfreserved2 = 0;
// Bfoffbits is the sum of the space required for the first three parts of the image file.
File. bfoffbits = 54 + colortablesize;
// Write the file header into the file
Fwrite (& file, sizeof (bitmapfileheader), 1, FP );
// Apply for bitmap information header Structure Variables and fill in information header information
Bitmapinfoheader head;
Head. bibitcount = bibitcount;
Head. biclrimportant = 0;
Head. biclrused = 0;
Head. bicompression = 0;
Head. biheight = height;
Head. biplanes = 1;
Head. bisize = 40;
Head. bisizeimage = linebyte * height;
Head. biwidth = width;
Head. bixpelspermeter = 0;
Head. biypelspermeter = 0;
// Write bitmap information header into memory
Fwrite (& head, sizeof (bitmapinfoheader), 1, FP );
// If the grayscale image has a color table, write it to a file
If (bibitcount = 8)
If (fwrite (pcolortable, sizeof (rgbquad), 256, FP )! = 256)
Printf ("/nwrite error/N ");
Else if (bibitcount = 1)
Fwrite (pcolortable, sizeof (rgbquad), 2, FP );
Else if (bibitcount = 4)
Fwrite (pcolortable, sizeof (rgbquad), 2 ^ 4, FP );
// Write bitmap data into the file
Fwrite (imgbuf, height * linebyte, 1, FP );
// Close the file
Fclose (FP );
Return 1;
}

 

// Main. c

# Include <stdio. h>
# Include "BMP. H"
# Include "BMP. H"
Unsigned char * pbmpbuf; // pointer for reading image data
Long BMP width; // Image Width
Long bmpheight; // Image Height
Rgbquad * pcolortable; // color table pointer
Int bibitcount; // image type, number of digits per pixel
Int linebyte;
Void main ()
{
Char readpath [] = "1.bmp ";
Readbmp (readpath );
Unsigned char * dataout;
Linebyte = (BMP width * 3 + 3)/4*4;
Int linebyteout = (BMP width * 3 + 3)/4*4;
Dataout = new unsigned char [linebyteout * bmpheight];
Int I, j, bibitcountout = 24;
For (I = 0; I <bmpheight; I ++)
{
For (j = 0; j <BMP width; j ++)
{
* (Dataout + I * linebyteout + J * 3 + 0) = 255-* (pbmpbuf + I * linebyte + J * 3 + 0 );
* (Dataout + I * linebyteout + J * 3 + 1) = 255-* (pbmpbuf + I * linebyte + J * 3 + 1 );
* (Dataout + I * linebyteout + J * 3 + 2) = 255-* (pbmpbuf + I * linebyte + J * 3 + 2 );
}
}

Printf ("% d, % d", BMP width, bibitcount );

Char writepath [] = "change.bmp ";
Savebmp (writepath, dataout, BMP width, bmpheight, bibitcountout, pcolortable );
// Clear the buffer
Delete [] dataout;
Delete [] pcolortable;
}