I m capturing images from camera, and I have two function for saving 16-bit(!) image one in PNG and one in TIFF formats. Could you please explain why the PNG is a very noisy image? like this:
PNG 函数 :
bool save_image_png(const char *file_name,const mono16bit& img)
{
[...]
/* write header */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during writing header");
png_set_IHDR(png_ptr, info_ptr, width, height,
bit_depth,PNG_COLOR_TYPE_GRAY , PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
png_write_info(png_ptr, info_ptr);
/* write bytes */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during writing bytes");
row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
for (y=0; y<height; y++)
row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr));
for (y = 0; y < height; y++)
{
row_pointers[y] = (png_bytep)img.getBuffer() + y * width*2;
}
png_write_image(png_ptr, row_pointers);
/* end write */
[...]
}
TIFF 函数 :
bool save_image(const char *fname,const mono16bit& img)
{
[...]
for(y=0; y<height; y++) {
if((err=TIFFWriteScanline(tif,(tdata_t)(img.getBuffer()+width*y),y,0))==-1)
break;
}
TIFFClose(tif);
if(err==-1) {
fprintf(stderr,"Error writing to %s file
",fname);
return false;
}
return true;
//#endif //USE_LIBTIFF
}
谢谢!