To use the LibTiff library in C++ for reading and saving files from memory, you can perform the following steps:
#include <tiffio.h>
// Assume that 'data' is a pointer to the memory buffer containing the TIFF file
// 'size' is the size of the buffer
TIFF* tif = TIFFClientOpen("membuffer", "r", (thandle_t) data,
[](void*, void*, int){}, // read-only memory buffer
[](void*, void*, int){}, // no seek support
[](void*, uint64_t){}, // no close required
[](void*, void*, uint64_t) -> uint64_t { return 0;} // no size required
);
if (!tif)
// handle error
// Now read the image data from the TIFF file
uint32_t width, height;
TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &width);
TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &height);
void *buf = _aligned_malloc(TIFFScanlineSize(tif), TIFFScanlineSize(tif));
for (uint32_t row = 0; row < height; row++) {
TIFFReadScanline(tif, buf, row);
// buf now contains image data for this row, you can process it here
}
_aligned_free(buf);
// Close the TIFF file handle
TIFFClose(tif);
// Assume that 'data' is a pointer to the memory buffer where the TIFF file will be saved
// 'size' is the size of the buffer
TIFF* tif = TIFFClientOpen("membuffer", "w", (thandle_t) data,
[](void*, void*, int){}, // write-only memory buffer
[](void*, void*, int){}, // no seek support
[](void*, uint64_t){}, // no flush required
[](void*, void*, uint64_t) -> uint64_t { return 0;} // no size required
);
if (!tif)
// handle error
// Now set the TIFF parameters you want to use
uint32_t width = ...; // image width
uint32_t height = ...; // image height
uint16_t bits_per_sample[] = { 8 }; // bits per channel
TIFFSetField(tif, TIFFTAG_IMAGEWIDTH, width);
TIFFSetField(tif, TIFFTAG_IMAGELENGTH, height);
TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, 1); // grayscale image
TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, bits_per_sample);
TIFFSetField(tif, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
TIFFSetField(tif, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_MINISBLACK);
// Now write the image data to the TIFF file
void *buf = _aligned_malloc(TIFFScanlineSize(tif), TIFFScanlineSize(tif));
for (uint32_t row = 0; row < height; row++) {
// Fill buf with the image data for this row
TIFFWriteScanline(tif, buf, row);
}
_aligned_free(buf);
// Close the TIFF file handle
TIFFClose(tif);
Asked: 2022-12-05 11:00:00 +0000
Seen: 12 times
Last updated: Mar 04 '22