C + + Read the RGB value of the image (two methods, have been tested)

1, the use of magick++ read, applicable to a variety of picture formats (magick++ support)

Related information:

Http://www.imagemagick.org/Magick++/Image.html

Http://www.imagemagick.org/Magick++/Documentation.html

http://www.imagemagick.org/discourse-server/viewtopic.php?f=2&t=16625

int _tmain (int argc, _tchar* argv[]) {Geometry g (800, 533); Image thei; File* FH; float *floatpixelmap; try {thei.read (g, "./bluejay.jpg"); int height = thei.rows (); int width = Thei.columns (); int size = Height * Width * 4; pixelpacket* mymap = thei.getpixels (0, 0, width, height); Floatpixelmap = new Float[size]; for (int counter = 0, k=0 counter < size; counter++, ++k) {floatpixelmap[counter++] = (float) mymap[k].red/255.0f; f loatpixelmap[counter++] = (float) mymap[k].green/255.0f; floatpixelmap[counter++] = (float) mymap[k].blue/255.0f; Floatpixelmap[counter] = (float) mymap[k].opacity/255.0f; }//end for loop fh = fopen ("./bluejay32float.procd.rgba", "WB"); Fwrite (void *) Floatpixelmap, sizeof (float), size, FH); }//end try block catch (exception& ex) {cout << "imagicktstr,error," << ex.what () << Endl;} End catch blocks return 0; }//end Main

2, directly parse BMP file format, can only read BMP format

#include <string.h> #include <math.h> #include <stdio.h> #include <stdlib.h> #include < Malloc.h> #define Widthbytes (BITS) ((BITS)/32*4) typedef unsigned char byte;//character typedef unsigned short word;// integer typedef unsigned long dword;//-shape typedef A. Bitmap file header information structure definition//which does not contain file type information (due to the structure of the memory structure of the decision, if added will not read the correct file information) typedef struct TAGBITMAPFILEHEADER {//word bftype; DWORD bfsize; File size WORD bfReserved1; reserved word, do not consider word bfReserved2; reserved word, ibid. DWORD bfoffbits; The number of offset bytes of the actual bitmap data, that is, the first three-part length and} Bitmapfileheader; Information header Bitmapinfoheader, also a structure, is defined as follows: typedef struct tagbitmapinfoheader{//public:dword bisize;//Specify the length of this structure, for long Biwidth; Bitmap wide LONG biheight; Bitmap high WORD biplanes; Number of planes, for 1 WORD bibitcount; The use of color number, can be 1,2,4,8,16,24, the new can be a DWORD bicompression; Compression mode, can be 0,1,2, where 0 means not compressing the DWORD bisizeimage; The actual bitmap data occupies a number of bytes LONG bixpelspermeter; X direction resolution LONG Biypelspermeter; Y-directional resolution DWORD biclrused; The number of colors used, if 0, the default value (2^ color digits) DWORD biclrimportant; Number of important colors, if 0, all colorsare important} Bitmapinfoheader; Palette palette, of course, is for those bitmap files that require a palette. 24-bit and 32-bit are not required for palettes. (The number of colors that appear to be the palette structure equals that used.) ) typedef struct TAGRGBQUAD {//public:byte rgbblue;///blue component of the color byte rgbgreen;//green component of the color byte rgbred;//red component of the color byte RG breserved; Reserved value} Rgbquad; void Showrgbquan (tagrgbquad* prgb) {printf (%-3d,%-3d,%-3d), Prgb->rgbred,prgb->rgbgreen,prgb->rgbblue) ; int main () {char ch,pd; int b,c,m,d,w,e,f; int x,y; unsigned char *q; int i,j; unsigned char a[2]; char strfile[50]; Bitmapfileheader Bithead; Bitmapinfoheader Bitinfohead; Tagrgbquad *prgb; FILE *FP; FILE *p; q= (unsigned char*) malloc (1); printf ("mkx** in C language programming to read BMP file a pixel of data **/n Please enter a BMP file:/n"); scanf ("%s", strfile); Fp=fopen (strfile, "RB"); if (fp!=null) {printf ("File Open success!/n"); WORD FileType; Fread (&filetype,1,sizeof (WORD), FP); if (FileType!= 0x4d42) {printf ("file isn't. bmp file!"); System ("pause"); return 0;}} else {printf ("File Open fail!/n"); System ("pause"); return 0}//Read file header information and print the value fread of the file header information (&amP;bithead,1,sizeof (Tagbitmapfileheader), FP); printf ("BMP header information/n File size:%d/n reserved word:%d/n reserved word:%d/n offset bytes of actual bitmap data:%d/n/n", bithead.bfsize,bithead.bfreserved1, Bithead.bfreserved2,bithead.bfoffbits); Read the file information header and print the value of the file information header fread (&bitinfohead,1,sizeof (Tagbitmapinfoheader), FP); printf ("BMP File Information header/n struct Length:%d/n bitmap width:%d/n bitmap height:%d/nbiplanes plane number:%d/nbibitcount using color digits:%d/n compression mode:%d/ Nbisizeimage the number of bytes in the actual bitmap data:%d/nx Direction Resolution:%d/ny Direction Resolution:%d/n The number of colors used:%d/n Important colors:%d/n ", Bitinfohead.bisize, Bitinfohead.biwidth,bitinfohead.biheight,bitinfohead.biplanes,bitinfohead.bibitcount,bitinfohead.bicompression , bitinfohead.bisizeimage,bitinfohead.bixpelspermeter,bitinfohead.biypelspermeter,bitinfohead.biclrused, Bitinfohead.biclrimportant); if (Bitinfohead.bibitcount <) {printf ("The file has a palette, that is, the bitmap is a non true Color/n/n"); m=1 if (Bitinfohead.bibitcount =8) {long Nplantnum = Long (Pow (2,double (bitinfohead.bibitcount))); Mix Color plant number; prgb= (Tagrgbquad *) malloc (nplantnum*sizeof (Tagrgbquad)); memset (prgb,0,nplantnum*sizeof (Tagrgbquad)); int num = freAD (PRGB,4,NPLANTNUM,FP); printf ("Color Plate Number:%d/n", nplantnum); printf ("Color board information:/n"); for (int i =0; i<nplantnum;i++) {if (i%5==0) {printf ("/n");} Showrgbquan (&prgb[i]); printf ("n"); } else{printf ("This bitmap is a 24-bit true Color/n/n"); m=3;} fclose (FP); while (ch!= ' N ') {P=fopen (strfile, "RB"); ch=null; f=bitinfohead.biheight; e=bitinfohead.biwidth; b=bithead.bfoffbits; printf ("* * Enter the data for the specified pixel * * (row: 1~%d column 1~%d)/n", f,e); printf ("Please enter line I:"); scanf ("%d", &x); printf ("Please enter column J:"); scanf ("%d", &y); c=b+ (x-1) *e*m+m* (y-1); Fseek (p,c,0); printf ("%d/n", m); if (m<2) {fread (&a[0],1,1,p); printf ("Data of this pixel point (hexadecimal) is:%x, a[0]);" printf ("In decimal notation:%d/n", a[0]); D=A[0]; printf ("its corresponding RGB value is:"); Showrgbquan (&prgb[d]); printf ("n"); else {for (i=0;i<3;i++) {fread (&a[i],1,1,p);//printf ("%x/n", A[i]); printf ("Hexadecimal:/n blue:%x/n green:%x/n Red:%x/n", a [0],a[1],a[2]); printf ("Decimal representation:/n Blue:%d/n green:%d/n Red:%d/n", a[0],a[1],a[2)); } rewind (P); W=ftell (P); printf ("%d", W); Fclose (P); printf ("* * Continue Please enter any character, if you want to exit Please enter n/n"); GetChar (); scanf ("%c", &ch); printf ("Thank you for using ~/n"); System ("pause"); return 0; }