?? image.c
字號:
//分配浮點型的數據內存空間，這個是函數的輸出
pfimage=(PFIMAGE)malloc(sizeof(FIMAGE));
if (pfimage==NULL){
free(pimage);
return NULL;
}
//打開指定路徑的pgm圖像
if ((fp=fopen(PGMFileName, "rb"))==NULL){
free(pimage);
return NULL;
}
//處理文件頭
while ((ch != 'P') && (ch != '#')){
ch = fgetc(fp);
}
//跳過文件附件信息
PGMSkipComments(fp, &ch);
//規定支持打開的pgm類型為P5
ftype = fgetc(fp);
//異常處理
if (ftype != '5'){
ImageWarning("Only binary PGM is supported.\n");
free(pfimage);
free(pimage);
fclose(fp);
return NULL;
}
//獲取圖像的寬、高數值
pimage->xsize=(int)PGMGetVal(fp);
pimage->ysize=(int)PGMGetVal(fp);
//獲取圖像灰度值的最大值
MaxG=(int)PGMGetVal(fp);
//分配圖像數據的內存空間
if(!ImageBufferAlloc(pimage)){
free(pimage);
free(pfimage);
return NULL;
}
//從文件尾開始的指針偏移，以避免讀取無用的圖像附加信息
fseek(fp, -1*pimage->xsize * pimage->ysize, SEEK_END);
//加載圖像數據，如果發現數據的大小不匹配，則出錯退出，釋放原有的圖像數據空間，關閉已打開的pgm文件
if (fread(pimage->pixel[0], sizeof(unsigned char),
pimage->xsize*pimage->ysize, fp) != (unsigned int)pimage->xsize*pimage->ysize){
fclose(fp);
ImageBufferFree(pimage);
free(pimage);
free(pfimage);
return NULL;
}
fclose(fp);
//將數據類型轉換為浮點型
pfimage->xsize=pimage->xsize;
pfimage->ysize=pimage->ysize;
//分配內存空間
if(!FImageBufferAlloc(pfimage)){
free(pfimage);
ImageFree(pimage);
return NULL;
}
//將pimage中的數據轉換后拷貝到pfimage中，完成浮點轉換
for (i=0; i< pfimage->xsize*pfimage->ysize; i++){
pfimage->pixelLinear[i]=(double)pimage->pixelLinear[i];
}
//釋放暫存用的整形數據空間
ImageFree(pimage);
return pfimage;
}
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
int WritePGM(PIMAGE pimage, char *PGMFileName)
{
FILE *fp;
int i;
if ((fp=fopen(PGMFileName, "wb+"))==NULL){
return 0;
}
fprintf(fp, "P5\n#%s\n%d %d\n255\n", PGMFileName, pimage->xsize, pimage->ysize);
i=fwrite(pimage->pixel[0], sizeof(unsigned char),
(pimage->xsize)*(pimage->ysize), fp);
fclose(fp);
if (i!=(pimage->ysize)*(pimage->xsize)){
return 0;
}
else{
return i;
}
}
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
int WriteFloatToPGM(PFIMAGE pfimage, char *PGMFileName)
{
FILE *fp;
unsigned char **temp, *tempLinear;
int i;
temp=Byte_Alloc(pfimage->ysize, pfimage->xsize);
tempLinear=temp[0];
if (temp==NULL){
return 0;
}
if ((fp=fopen(PGMFileName, "wb+"))==NULL){
return 0;
}
fprintf(fp, "P5\n#%s\n%d %d\n255\n", PGMFileName, pfimage->xsize, pfimage->ysize);
/* Copy */
for (i=0; i<pfimage->xsize*pfimage->ysize; i++){
tempLinear[i]=(int)((pfimage->pixelLinear[i]+0.5) < 0.0 ? 0 :
((pfimage->pixelLinear[i]+0.5) > 255.0 ? 255 :
(pfimage->pixelLinear[i]+0.5)));
}
i=fwrite(temp[0], sizeof(unsigned char), (pfimage->xsize)*(pfimage->ysize), fp);
fclose(fp);
free(temp[0]);
free(temp);
if (i!=(pfimage->ysize)*(pfimage->xsize)){
return 0;
}
else{
return i;
}
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Get a number from a pgm file header, skipping comments etc. */
unsigned int PGMGetVal (FILE* infile)
{
unsigned int tmp;
unsigned char ch;
do {
ch = fgetc(infile);
} while ((ch <= ' ') && (ch != '#'));
PGMSkipComments(infile, &ch);
ungetc(ch, infile);
/* Do not understand this part */
if (fscanf(infile,"%u",&tmp) != 1) {
ImageError("%s\n","Error parsing file!");
}
return(tmp);
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
void PGMSkipComments(FILE* infile, unsigned char *ch)
{
while ((*ch == '#')){
while (*ch != '\n'){
*ch = fgetc(infile);
}
while (*ch < ' '){
*ch = fgetc(infile);
}
}
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
double ImageCompareMSE(PIMAGE pimage1, PIMAGE pimage2)
{
int i;
double Error, SumOfSquareError=0.0;
if ((pimage1->xsize != pimage2->xsize) || (pimage1->ysize!=pimage2->ysize)){
ImageWarning("Cannot compare images of different sizes (%dx%d and %dx%d)\n",
pimage1->xsize, pimage1->ysize, pimage2->xsize, pimage2->ysize);
return 0.0;
}
for (i=0; i< pimage1->xsize*pimage1->ysize; i++){
Error=pimage1->pixelLinear[i]-pimage2->pixelLinear[i];
SumOfSquareError+=Error*Error;
}
return SumOfSquareError/(double)(pimage1->xsize*pimage1->ysize);
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
double ImageComparePSNR(PIMAGE pimage1, PIMAGE pimage2)
{
int i;
double Error, SumOfSquareError=0.0, RootMeanSquareError;
if ((pimage1->xsize != pimage2->xsize) || (pimage1->ysize!=pimage2->ysize)){
ImageWarning("Cannot compare images of different sizes (%dx%d and %dx%d)\n",
pimage1->xsize, pimage1->ysize, pimage2->xsize, pimage2->ysize);
return 0.0;
}
for (i=0; i< pimage1->xsize*pimage1->ysize; i++){
Error=pimage1->pixelLinear[i]-pimage2->pixelLinear[i];
SumOfSquareError+=Error*Error;
}
RootMeanSquareError = sqrt(SumOfSquareError/(double)(pimage1->xsize*pimage1->ysize));
return 20*log10(255.0/RootMeanSquareError); /* assume maximum 255 */
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
double FImageCompareMSE(PFIMAGE pfimage1, PFIMAGE pfimage2)
{
int i;
double Error, SumOfSquareError=0.0;
if ((pfimage1->xsize != pfimage2->xsize) || (pfimage1->ysize!=pfimage2->ysize)){
ImageWarning("Cannot compare images of different sizes (%dx%d and %dx%d)\n",
pfimage1->xsize, pfimage1->ysize, pfimage2->xsize, pfimage2->ysize);
return 0.0;
}
for (i=0; i< pfimage1->xsize*pfimage1->ysize; i++){
Error=pfimage1->pixelLinear[i]-pfimage2->pixelLinear[i];
SumOfSquareError+=Error*Error;
}
return SumOfSquareError/(double)(pfimage1->xsize*pfimage1->ysize);
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
double FImageComparePSNR(PFIMAGE pfimage1, PFIMAGE pfimage2)
{
int i;
double Error, SumOfSquareError=0.0, RootMeanSquareError;
if ((pfimage1->xsize != pfimage2->xsize) || (pfimage1->ysize!=pfimage2->ysize)){
ImageWarning("Cannot compare images of different sizes (%dx%d and %dx%d)\n",
pfimage1->xsize, pfimage1->ysize, pfimage2->xsize, pfimage2->ysize);
return 0.0;
}
for (i=0; i< pfimage1->xsize*pfimage1->ysize; i++){
Error=pfimage1->pixelLinear[i]-pfimage2->pixelLinear[i];
SumOfSquareError+=Error*Error;
}
RootMeanSquareError = sqrt(SumOfSquareError/(double)(pfimage1->xsize*pfimage1->ysize));
return 20*log10(255.0/RootMeanSquareError); /* assume maximum 255 */
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* RGB to YCbCr */
void rgb2ycc(double r, double g, double b, double *y, double *cb, double *cr)
{
(*y) = 0.29900*r + 0.58700*g + 0.11400*b;
(*cb) = -0.16874*r - 0.33126*g + 0.50000*b + 128.0;
(*cr) = 0.50000*r - 0.41869*g - 0.08131*b + 128.0;
return;
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* YCbCr to RGB */
void ycc2rgb(double y,double cb, double cr, double *r, double *g, double *b)
{
cb = cb - 128.0;
cr = cr - 128.0;
(*r) = y + 1.40200*cr;
(*g) = y - 0.34414*cb - 0.71414*cr;
(*b) = y + 1.77200*cb;
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Rescales a matrix using bicubic spline interpolation
* (taken from Nachtwerk audioDSP library). Coded by Makus Fick
*
*/
PIMAGE RescaleImage(PIMAGE pimageSrc, int newWidth, int newHeight, double zeroVal)
{
int srcXI, srcYI;
int xx, yy;
int width, height;
double xstep, ystep;
double **matrix1, **matrix2;
double srcX, srcXF, srcY, srcYF;
double ip0, ip1, ip2, ip3, a0, a1, a2, a3, yd1, yd2, yd3, inv;
PIMAGE pimageDest;
width = pimageSrc->xsize;
height= pimageSrc->ysize;
xstep = ((double)width) / ((double)newWidth);
ystep = ((double)height) / ((double)newHeight);
pimageDest = ImageAlloc(newWidth, newHeight);
if (pimageDest==NULL){
return NULL;
}
if ((matrix1 = Double_Alloc(height, newWidth))==NULL){
ImageFree(pimageDest);
return NULL;
}
if ((matrix2 = Double_Alloc(newHeight, newWidth))==NULL){
ImageFree(pimageDest);
free(matrix1[0]);
return NULL;
}
/* first step: decimate width */
if( newWidth != width ){
for (yy=0; yy < height; yy++ ){
for (xx=0; xx<newWidth; xx++){
srcX = xstep*xx;
srcXI= (int)srcX;
srcXF= srcX - (double)srcXI;
ip0 = (( ( srcXI < 0 ) || ( srcXI >= width ) ) ? zeroVal : pimageSrc->pixel[yy][srcXI]);
ip1 = (( ( srcXI+1 < 0 ) || ( srcXI+1 >= width ) ) ? zeroVal : pimageSrc->pixel[yy][srcXI+1]);
ip2 = (( ( srcXI+2 < 0 ) || ( srcXI+2 >= width ) ) ? zeroVal : pimageSrc->pixel[yy][srcXI+2]);
ip3 = (( ( srcXI+3 < 0 ) || ( srcXI+3 >= width ) ) ? zeroVal : pimageSrc->pixel[yy][srcXI+3]);
a0 = ip0;
a1 = ( 7.0 * ip3 - 31.5 * ip2 + 63.0 * ip1 - 38.5 * ip0) / 21.0;
yd1 = (-3.5 * ip3 + 21.0 * ip2 - 10.5 * ip1 - 7.0 * ip0) / 21.0;
yd2 = ip1 - ip0;
yd3 = a1 + yd1;
a3 = yd3 - 2.0 * yd2;
a2 = yd2 - a3 - a1;
inv = ((a3 * srcXF + a2)* srcXF + a1)* srcXF + a0;
inv = (inv < 0.0) ? 0.0 : ((inv > 255.0) ? 255.0 : inv);
matrix1[yy][xx] = inv;
}
}
}
else{
for(yy=0; yy<height; yy++ ){
for(xx=0; xx<width; xx++ ){
matrix1[yy][xx] = pimageSrc->pixel[yy][xx];
}
}
}
/* second step: decimate height */
if (newHeight != height){
for( xx=0; xx<newWidth; xx++){
for( yy=0; yy<newHeight; yy++ ){
srcY = ystep*yy;
srcYI = (int)srcY;
srcYF = srcY - (double)srcYI;
ip0 = (( ( srcYI < 0 ) || ( srcYI >= height ) ) ? zeroVal : matrix1[srcYI ][xx]);
ip1 = (( ( srcYI+1 < 0 ) || ( srcYI+1 >= height ) ) ? zeroVal : matrix1[srcYI+1][xx]);
ip2 = (( ( srcYI+2 < 0 ) || ( srcYI+2 >= height ) ) ? zeroVal : matrix1[srcYI+2][xx]);
ip3 = (( ( srcYI+3 < 0 ) || ( srcYI+3 >= height ) ) ? zeroVal : matrix1[srcYI+3][xx]);
a0 = ip0;
a1 = ( 7.0 * ip3 - 31.5 * ip2 + 63.0 * ip1 - 38.5 * ip0) / 21.0;
yd1 = (-3.5 * ip3 + 21.0 * ip2 - 10.5 * ip1 - 7.0 * ip0) / 21.0;
yd2 = ip1 - a0;
yd3 = a1 + yd1;
a3 = yd3 - 2.0 * yd2;
a2 = yd2 - a3 - a1;
inv = ((a3 * srcYF + a2) * srcYF + a1)* srcYF + a0;
inv = (inv < 0.0) ? 0.0 : ((inv > 255.0) ? 255.0 : inv);
matrix2[yy][xx] = inv;
}
}
}
else{
for(xx=0; xx<newWidth; xx++ ){
for(yy=0; yy<height; yy++ ){
matrix2[yy][xx] = matrix1[yy][xx];
}
}
}
/* copy */
for (yy=0; yy<newHeight; yy++){
for (xx=0; xx<newWidth; xx++){
pimageDest->pixel[yy][xx]=(unsigned char)matrix2[yy][xx];
}
}
free(matrix1[0]);
free(matrix2[0]);
return pimageDest;
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
void ImageError(char *fmt, ...)
{
va_list argptr;
va_start( argptr, fmt );
fprintf(stderr, "ImageError: " );
vprintf( fmt, argptr );
va_end( argptr );
exit( -1 );
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
void ImageWarning(char *fmt, ...)
{
va_list argptr;
va_start( argptr, fmt );
fprintf( stderr, "ImageWarning: " );
vprintf( fmt, argptr );
va_end( argptr );
}
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