BMP图片转JPEG图片C程序源代码.doc

/ A BMP truecolor to JPEG encoder/ Copyright 1999 Cristian Cuturicu#include #include #include #include jtypes.h#include jglobals.h#include jtables.hvoid write_APP0info()/Nothing to overwrite for APP0infowriteword(APP0info.marker);writeword(APP0info.length);writebyte(J);writebyte(F);writebyte(I);writebyte(F);writebyte(0);writebyte(APP0info.versionhi);writebyte(APP0info.versionlo);writebyte(APP0info.xyunits);writeword(APP0info.xdensity);writeword(APP0info.ydensity);writebyte(APP0info.thumbnwidth);writebyte(APP0info.thumbnheight);void write_SOF0info()/ We should overwrite width and heightwriteword(SOF0info.marker);writeword(SOF0info.length);writebyte(SOF0info.precision);writeword(SOF0info.height);writeword(SOF0info.width);writebyte(SOF0info.nrofcomponents);writebyte(SOF0info.IdY);writebyte(SOF0info.HVY);writebyte(SOF0info.QTY);writebyte(SOF0info.IdCb);writebyte(SOF0info.HVCb);writebyte(SOF0info.QTCb);writebyte(SOF0info.IdCr);writebyte(SOF0info.HVCr);writebyte(SOF0info.QTCr);void write_DQTinfo()BYTE i;writeword(DQTinfo.marker);writeword(DQTinfo.length);writebyte(DQTinfo.QTYinfo);for (i=0; i64; i+) writebyte(DQTinfo.Ytablei);writebyte(DQTinfo.QTCbinfo);for (i=0; i64; i+) writebyte(DQTinfo.Cbtablei);void set_quant_table(BYTE *basic_table, BYTE scale_factor, BYTE *newtable)/ Set quantization table and zigzag reorder itBYTE i;long temp;for (i=0; i64; i+) temp = (long) basic_tablei * scale_factor + 50L) / 100L;/ limit the values to the valid rangeif (temp 255L) temp = 255L; newtablezigzagi = (BYTE) temp;void set_DQTinfo()BYTE scalefactor = 50;/ scalefactor controls the visual quality of the image/ the smaller is the better image well get, and the smaller / compression well achieveDQTinfo.marker = 0xFFDB;DQTinfo.length = 132;DQTinfo.QTYinfo = 0;DQTinfo.QTCbinfo = 1;set_quant_table(std_luminance_qt, scalefactor, DQTinfo.Ytable);set_quant_table(std_chrominance_qt, scalefactor, DQTinfo.Cbtable);void write_DHTinfo()BYTE i;writeword(DHTinfo.marker);writeword(DHTinfo.length);writebyte(DHTinfo.HTYDCinfo);for (i=0; i16; i+) writebyte(DHTinfo.YDC_nrcodesi);for (i=0; i12; i+) writebyte(DHTinfo.YDC_valuesi);writebyte(DHTinfo.HTYACinfo);for (i=0; i16; i+)writebyte(DHTinfo.YAC_nrcodesi);for (i=0; i162; i+) writebyte(DHTinfo.YAC_valuesi);writebyte(DHTinfo.HTCbDCinfo);for (i=0; i16; i+) writebyte(DHTinfo.CbDC_nrcodesi);for (i=0; i12; i+)writebyte(DHTinfo.CbDC_valuesi);writebyte(DHTinfo.HTCbACinfo);for (i=0; i16; i+)writebyte(DHTinfo.CbAC_nrcodesi);for (i=0; i162; i+)writebyte(DHTinfo.CbAC_valuesi);void set_DHTinfo()BYTE i;/ fill the DHTinfo structure get the values from the standard Huffman tablesDHTinfo.marker = 0xFFC4;DHTinfo.length = 0x01A2;DHTinfo.HTYDCinfo = 0;for (i=0; i16; i+)DHTinfo.YDC_nrcodesi = std_dc_luminance_nrcodesi+1;for (i=0; i12; i+)DHTinfo.YDC_valuesi = std_dc_luminance_valuesi;DHTinfo.HTYACinfo = 0x10;for (i=0; i16; i+)DHTinfo.YAC_nrcodesi = std_ac_luminance_nrcodesi+1;for (i=0; i162; i+)DHTinfo.YAC_valuesi = std_ac_luminance_valuesi;DHTinfo.HTCbDCinfo = 1;for (i=0; i16; i+)DHTinfo.CbDC_nrcodesi = std_dc_chrominance_nrcodesi+1;for (i=0; i12; i+)DHTinfo.CbDC_valuesi = std_dc_chrominance_valuesi;DHTinfo.HTCbACinfo = 0x11;for (i=0; i16; i+)DHTinfo.CbAC_nrcodesi = std_ac_chrominance_nrcodesi+1;for (i=0; i162; i+)DHTinfo.CbAC_valuesi = std_ac_chrominance_valuesi;void write_SOSinfo()/Nothing to overwrite for SOSinfowriteword(SOSinfo.marker);writeword(SOSinfo.length);writebyte(SOSinfo.nrofcomponents);writebyte(SOSinfo.IdY);writebyte(SOSinfo.HTY);writebyte(SOSinfo.IdCb);writebyte(SOSinfo.HTCb);writebyte(SOSinfo.IdCr);writebyte(SOSinfo.HTCr);writebyte(SOSinfo.Ss);writebyte(SOSinfo.Se);writebyte(SOSinfo.Bf);void write_comment(BYTE *comment)WORD i, length;writeword(0xFFFE); / The COM markerlength = strlen(const char *)comment);writeword(length + 2);for (i=0; ilength; i+) writebyte(commenti);void writebits(bitstring bs)/ A portable version; it should be done in assemblerWORD value;SBYTE posval;/ bit position in the bitstring we read, should be =0 value = bs.value;posval = bs.length - 1;while (posval = 0)if (value & maskposval) bytenew |= maskbytepos;posval-;bytepos-;if (bytepos 0) / write itif (bytenew = 0xFF) / special casewritebyte(0xFF);writebyte(0);else writebyte(bytenew);/ reinitbytepos = 7;bytenew = 0;void compute_Huffman_table(BYTE *nrcodes, BYTE *std_table, bitstring *HT)BYTE k,j;BYTE pos_in_table;WORD codevalue;codevalue = 0; pos_in_table = 0;for (k=1; k=16; k+)for (j=1; j=nrcodesk; j+) HTstd_tablepos_in_table.value = codevalue;HTstd_tablepos_in_table.length = k;pos_in_table+;codevalue+;codevalue = 1;void init_Huffman_tables()/ Compute the Huffman tables used for encodingcompute_Huffman_table(std_dc_luminance_nrcodes, std_dc_luminance_values, YDC_HT);compute_Huffman_table(std_ac_luminance_nrcodes, std_ac_luminance_values, YAC_HT);compute_Huffman_table(std_dc_chrominance_nrcodes, std_dc_chrominance_values, CbDC_HT);compute_Huffman_table(std_ac_chrominance_nrcodes, std_ac_chrominance_values, CbAC_HT);void exitmessage(char *error_message)printf(%sn,error_message);exit(EXIT_FAILURE);void set_numbers_category_and_bitcode()SDWORD nr;SDWORD nrlower, nrupper;BYTE cat;category_alloc = (BYTE *)malloc(65535*sizeof(BYTE);if (category_alloc = NULL) exitmessage(Not enough memory.);/allow negative subscriptscategory = category_alloc + 32767; bitcode_alloc=(bitstring *)malloc(65535*sizeof(bitstring);if (bitcode_alloc=NULL) exitmessage(Not enough memory.);bitcode = bitcode_alloc + 32767;nrlower = 1;nrupper = 2;for (cat=1; cat=15; cat+) /Positive numbersfor (nr=nrlower; nrnrupper; nr+) categorynr = cat;bitcodenr.length = cat;bitcodenr.value = (WORD)nr;/Negative numbersfor (nr=-(nrupper-1); nr=-nrlower; nr+) categorynr = cat;bitcodenr.length = cat;bitcodenr.value = (WORD)(nrupper-1+nr);nrlower = 1;nrupper = 1;void precalculate_YCbCr_tables()WORD R,G,B;for (R=0; R256; R+) YRtabR = (SDWORD)(65536*0.299+0.5)*R;CbRtabR = (SDWORD)(65536*-0.16874+0.5)*R;CrRtabR = (SDWORD)(32768)*R;for (G=0; G256; G+) YGtabG = (SDWORD)(65536*0.587+0.5)*G;CbGtabG = (SDWORD)(65536*-0.33126+0.5)*G;CrGtabG = (SDWORD)(65536*-0.41869+0.5)*G;for (B=0; B256; B+) YBtabB = (SDWORD)(65536*0.114+0.5)*B;CbBtabB = (SDWORD)(32768)*B;CrBtabB = (SDWORD)(65536*-0.08131+0.5)*B;/ Using a bit modified form of the FDCT routine from IJGs C source:/ Forward DCT routine idea taken from Independent JPEG Groups C source for/ JPEG encoders/decoders/* For float AA&N IDCT method, divisors are equal to quantization coefficients scaled by scalefactorrow*scalefactorcol, where scalefactor0 = 1 scalefactork = cos(k*PI/16) * sqrt(2) for k=1.7 We apply a further scale factor of 8. Whats actually stored is 1/divisor so that the inner loop can use a multiplication rather than a division. */void prepare_quant_tables()double aanscalefactor8 = 1.0, 1.387039845, 1.306562965, 1.175875602,1.0, 0.785694958, 0.541196100, 0.275899379;BYTE row, col;BYTE i = 0;for (row = 0; row 8; row+)for (col = 0; col 8; col+)fdtbl_Yi = (float) (1.0 / (double) DQTinfo.Ytablezigzagi *aanscalefactorrow * aanscalefactorcol * 8.0);fdtbl_Cbi = (float) (1.0 / (double) DQTinfo.Cbtablezigzagi *aanscalefactorrow * aanscalefactorcol * 8.0);i+;void fdct_and_quantization(SBYTE *data, float *fdtbl, SWORD *outdata)float tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;float tmp10, tmp11, tmp12, tmp13;float z1, z2, z3, z4, z5, z11, z13;float *dataptr;float datafloat64;float temp;SBYTE ctr;BYTE i;for (i=0; i= 0; ctr-) tmp0 = dataptr0 + dataptr7;tmp7 = dataptr0 - dataptr7;tmp1 = dataptr1 + dataptr6;tmp6 = dataptr1 - dataptr6;tmp2 = dataptr2 + dataptr5;tmp5 = dataptr2 - dataptr5;tmp3 = dataptr3 + dataptr4;tmp4 = dataptr3 - dataptr4;/* Even part */tmp10 = tmp0 + tmp3;/* phase 2 */tmp13 = tmp0 - tmp3;tmp11 = tmp1 + tmp2;tmp12 = tmp1 - tmp2;dataptr0 = tmp10 + tmp11; /* phase 3 */dataptr4 = tmp10 - tmp11;z1 = (tmp12 + tmp13) * (float) 0.707106781); /* c4 */dataptr2 = tmp13 + z1;/* phase 5 */dataptr6 = tmp13 - z1;/* Odd part */tmp10 = tmp4 + tmp5;/* phase 2 */tmp11 = tmp5 + tmp6;tmp12 = tmp6 + tmp7;/* The rotator is modified from fig 4-8 to avoid extra negations. */z5 = (tmp10 - tmp12) * (float) 0.382683433); /* c6 */z2 = (float) 0.541196100) * tmp10 + z5; /* c2-c6 */z4 = (float) 1.306562965) * tmp12 + z5; /* c2+c6 */z3 = tmp11 * (float) 0.707106781); /* c4 */z11 = tmp7 + z3;/* phase 5 */z13 = tmp7 - z3;dataptr5 = z13 + z2;/* phase 6 */dataptr3 = z13 - z2;dataptr1 = z11 + z4;dataptr7 = z11 - z4;dataptr += 8;/* advance pointer to next row */ /* Pass 2: process columns. */dataptr = datafloat;for (ctr = 7; ctr = 0; ctr-) tmp0 = dataptr0 + dataptr56;tmp7 = dataptr0 - dataptr56;tmp1 = dataptr8 + dataptr48;tmp6 = dataptr8 - dataptr48;tmp2 = dataptr16 + dataptr40;tmp5 = dataptr16 - dataptr40;tmp3 = dataptr24 + dataptr32;tmp4 = dataptr24 - dataptr32;/* Even part */tmp10 = tmp0 + tmp3;/* phase 2 */tmp13 = tmp0 - tmp3;tmp11 = tmp1 + tmp2;tmp12 = tmp1 - tmp2;dataptr0 = tmp10 + tmp11; /* phase 3 */dataptr32 = tmp10 - tmp11;z1 = (tmp12 + tmp13) * (float) 0.707106781); /* c4 */dataptr16 = tmp13 + z1; /* phase 5 */dataptr48 = tmp13 - z1;/* Odd part */tmp10 = tmp4 + tmp5;/* phase 2 */tmp11 = tmp5 + tmp6;tmp12 = tmp6 + tmp7;/* The rotator is modified from fig 4-8 to avoid extra negations. */z5 = (tmp10 - tmp12) * (float) 0.382683433); /* c6 */z2 = (float) 0.541196100) * tmp10 + z5; /* c2-c6 */z4 = (float) 1.306562965) * tmp12 + z5; /* c2+c6 */z3 = tmp11 * (float) 0.707106781); /* c4 */z11 = tmp7 + z3;/* phase 5 */z13 = tmp7 - z3;dataptr40 = z13 + z2; /* phase 6 */dataptr24 = z13 - z2;dataptr8 = z11 + z4;dataptr56 = z11 - z4;dataptr+;/* advance pointer to next column */* Quantize/descale the coefficients, and store into output array */for (i = 0; i 64; i+) /* Apply the quantization and scaling factor */temp = datafloati * fdtbli;/* Round to nearest integer. Since C does not specify the direction of rounding for negative quotients, we have to force the dividend positive for portability. The maximum coefficient size is +-16K (for 12-bit data), so this code should work for either 16-bit or 32-bit ints. */outdatai = (SWORD) (SWORD)(temp + 16384.5) - 16384);void process_DU(SBYTE *ComponentDU,float *fdtbl,SWORD *DC, bitstring *HTDC,bitstring *HTAC)bitstring EOB = HTAC0x00;bitstring M16zeroes = HTAC0xF0;BYTE i;BYTE startpos;BYTE end0pos;BYTE nrzeroes;BYTE nrmarker;SWORD Diff;fdct_and_quantization(ComponentDU, fdtbl, DU_DCT);/ zigzag reorderfor (i=0; i0)&(DUend0pos=0); end0pos-) ;/end0pos = first element in reverse order != 0i = 1;while (i = end0pos)startpos = i;for (; (DUi=0) & (i= 16) for (nrmarker=1; nrmarker=nrzeroes/16; nrmarker+) writebits(M16zeroes);nrzeroes = nrzeroes%16;writebits(HTACnrzeroes*16+categoryDUi);writebits(bitcodeDUi);i+;if (end0pos != 63) writebits(EOB);void load_data_units_from_RGB_buffer(WORD xpos, WORD ypos)BYTE x, y;BYTE pos = 0;DWORD location;BYTE R, G, B;location = ypos * width + xpos;for (y=0; y8; y+)for (x=0; x8; x+)R = RGB_bufferlocation.R;G = RGB_bufferlocation.G;B = RGB_bufferlocation.B;/ convert to YCbCrYDUpos = Y(R,G,B);CbDUpos = Cb(R,G,B);CrDUpos = Cr(R,G,B);location+;pos+;location += width - 8;void main_encoder()SWORD DCY = 0, DCCb = 0, DCCr = 0; /DC coefficients used for differential encodingWORD xpos, ypos;for (ypos=0; yposheight; ypos+=8)for (xpos=0; xposwidth; xpos+=8)load_data_units_from_RGB_buffer(xpos, ypos);process_DU(YDU, fdtbl_Y, &DCY, YDC_HT, YAC_HT);process_DU(CbDU, fdtbl_Cb, &DCCb, CbDC_HT, CbAC_HT);process_DU(CrDU, fdtbl_Cb, &DCCr, CbDC_HT, CbAC_HT);void load_bitmap(char *bitmap_name, WORD *width_original, WORD *height_original)WORD widthDiv8, heightDiv8; / closest multiple of 8 ceilBYTE nr_fillingbytes;/The number of the filling bytes in the BMP file / (the dimension in bytes of a BMP line on the disk is divisible by 4)colorRGB lastcolor;WORD column;BYTE TMPBUF256;WORD nrline_up, nrline_dn, nrline;WORD dimline;colorRGB *tmpline;FILE *fp_bitmap = fopen(bitmap_name,rb);if (fp_bitmap=NULL) exitmessage(Cannot open bitmap file.File not found ?);if (fread(TMPBUF, 1, 54, fp_bitmap) != 54)exitmessage(Need a truecolor BMP to encode.);if (TMPBUF0!=B)|(TMPBUF1!=M)|(TMPBUF28!=24)exitmessage(Need a truecolor BMP to encode.);width = (WORD)TMPBUF19*256+TMPBUF18;height = (WORD)TMPBUF23*256+TMPBUF22;/ Keep the old dimensions of the image*width_original = width;*height_original = height; if (width%8 != 0) widthDiv8 = (width/8)*8+8;else widthDiv8 = width;if (height%8 != 0) heightDiv8 = (height/8)*8+8;else heightDiv8 = height;/ The image we encode shall be filled with the last line and the last column/ from the original bitmap, until width and height are divisible by 8/ Load BMP image from disk and complete XRGB_buffer = (colorRGB *)(malloc(3*widthDiv8*heightDiv8);if (RGB_buffer = NULL) exitmessage(Not enough memory for the bitmap image.);if ( (width*3)%4 != 0) nr_fillingbytes = 4 - ( (width*3)%4);else nr_fillingbytes = 0;for (nrline=0; nrlineheight; nrline+)fread(RGB_buffer + nrline*widthDiv8, 1, width*3, fp_bitmap);fread(TMPBUF, 1, nr_fillingbytes, fp_bitmap);/ complete Xmemcpy(&lastcolor, RGB_buffer + nrline*widthDiv8 + width-1, 3);for (column=width; columnnrline_dn; nrline_up-,nrline_dn+)memcpy(tmpline, RGB_buffer+nrline_up*width, dimline);memcpy(RGB_buffer+nrline_up*width, RGB_buffer+nrline_dn*width, dimline);memcpy(RGB_buffer+nrline_dn*width, tmpline, dimline);/ Y completion:memcpy(tmpline, RGB_buffer+(height-1)*width, dimline);for (nrline=height; nrline1) strcpy(BMP_filename,argv1);if (argc2) strcpy(JPG_filename,argv2);else / replace .bmp with .jpgstrcpy(JPG_filename, BMP_filename);len_filename=strlen(BMP_filename);strcpy(JPG_filename+(len_filename-3),jpg);else exitmessage(Syntax: enc fis.bmp fis.jpg);load_bitmap(BMP_filename, &width_original, &height_original);fp_jpeg_stream = fopen(JPG_filename,wb);init_all();SOF0info.width = width_original;SOF0info.height = height_original;writeword(0xFFD8); / SOIwrite_APP0info();/ write_comment(Cris made this JPEG with his own encoder);write_DQTinfo();write_SOF0info();write_DHTinf