Digital Image Processing-Learning summary

VC + + Digital Image processing Yang Shuxiang

This article to the teacher's code summary, code small white by the way to add their own more confused knowledge points, convenient follow-up review.

• The image structure for BMP format is divided into the following four parts:

Bitmap File Header structure Bitmapfileheader

Bitmap Information Header Structure Bitmapinfoheader

Bitmap Color Table Rgbquad

Bit image Prime Data part

• The image for the bitmap is divided into four categories:

1. Monochrome Image: There are two values: 0,255 where 0 means black, 255 is white (also can be normalized to 0 and 1).
2. Grayscale Image: With a color table, equivalent to an index table. RGB has the same component value.
3. Pseudo-color Image: RGB components are not exactly the same, with a color table, equivalent to the index, the entire image of 256 colors.
4. 24-bit True color Image: No color table, RGB three components accounted for 8 bits.

• For a description of struct structure in C + +:

In C + + if a typedef is used:

　　　　struct Student
{   
int A;  
}stu1;//STU1 is a variable

　　　　typedef struct STUDENT2
{   
int A;  
}STU2; STU2 is a struct type =struct Student

That is, using a typedef in C + + is equivalent to renaming an operation, which is equivalent to renaming a variable behind a struct.

• For type aliasing problems in variables-Introduce the header file "WindowsX.h"

windef.h--basic form definition
Winbase.h--kernel function
wingdi.h--Graphics Device Interface functions
winuser.h--User Interface functions

Here the main use is the first application: the basic shape definition, which defines the macro, convenient for later use.

1 Long 2 int                 BOOL;          3 Char 4 short      WORD;          5 float               FLOAT;

So the format of BMP image can be displayed in code way

Bitmap File Header:

1typedefstructTagbitmapfileheader2 {3WORD Bftype;//represents a 2-byte, 16-bit short integer that is used to determine whether the bitmap file type4DWORD bfsize;//represents the size of a 4-byte bitmap file. 5WORD bfReaserved1;//the reserved word for the bitmap file must be 0.6WORD BfReaserved2;//reserved word for bitmap file, must be 07DWORD bfoffbits;//represents the starting position of the data8} Bitmapfileheader;

Bitmap Information Header:

typedefstructTagbitmapinfoheader{dword bisize;//number of bytes occupied by this structureLONG Biwidth;//the width of the bitmap, in pixelsLONG Biheight;//the height of the bitmap, in pixelsWORD biplanes;//the level of the target device must be 1WORD biBitCount;//number of bits required per pixel, 1, 4, 8,DWORD bicompression;/*bitmap compression type, must be one of 0 (uncompressed), 1 (bi_rle8 compression type), 2 (bi_rle4 compression type)*/DWORD biSizeImage;//the size of the bitmap, in bytesLONG Bixpelspermeter;//Bitmap Horizontal resolution, pixels per metreLONG Biypelspermeter;//Bitmap vertical resolution, pixels per metreDWORD biclrused;//The number of colors that the bitmap actually uses for the color tableDWORD biclrimportant;//number of important colors during bitmap display}bitmapinfoheader;

Color table:

struct tagrgbquad{byte Rgbblue; // Blue Brightness (0~255) BYTE Rgbgreen; // Green BYTE rgbred; // Red BYTE rgbreserved; // reserved, must be 0} Rgbquad;

After the construction of the structure is finished, the class of BMP file is constructed:

Digital Image Processing-Learning summary