我想使用"libtiff"库从".tiff"图像中读取u8位像素强度值。 我遇到了这段代码并对其进行了修改以根据需要读取 8 位值,并仅返回一列的正确值。
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#include "tiffio.h"
#define imsize 286628
int count;
int count2;
uint8* im;
uint32 imagelength;
uint32 width;
int main(){
im = (uint8*)malloc(imsize*sizeof(uint8));
TIFF* tif = TIFFOpen("image1.tif", "r");
if (tif) {
tsize_t scanline;
tdata_t buf;
uint32 row;
uint32 col;
uint16 nsamples;
TIFFGetField(tif, TIFFTAG_SAMPLESPERPIXEL, &nsamples);
TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &imagelength);
TIFFGetField(tif,TIFFTAG_IMAGEWIDTH,&width);
scanline = TIFFScanlineSize(tif);
buf = _TIFFmalloc(scanline);
uint8* data;
for (row = 0; row < imagelength; row++)
{
TIFFReadScanline(tif, buf, row,1);
count2++;
for (col = 0; col < scanline; col++)
data = (uint8*)buf;
//printf("%dn",col); remains the same not incrementing
printf("%d ", *data);//printing for testing need only to copy to an array to access by index
im[count] = *data;
count++;
printf("n");
}
printf("im[1]= %dn im[2] = %d n im[3] = %d n im[286628] = %dn",im[0],im[1],im[2],im[286627]);
_TIFFfree(buf);
TIFFClose(tif);
free(im);
}
printf("num of cols= %dn",count);
printf("num of rows = %dn",count2);//both counts print col size
printf("width = %dn",width); //prints row size
return 0;
}
在嵌套的forloop中,如果我添加括号,循环迭代正确的像素数(对于此示例,#of 像素 = 286628,547x524 图像),但值不正确。如果我删除括号,我会得到正确的值,但对于第一列(只有 547 个值)。
需要进行哪些更改才能正确迭代所有像素?
注意:我正在尝试获取一个值为 matlabs "imread()" 的矩阵
在col
循环中,每列使用data = (uint8*)buf;
执行完全相同的操作,这似乎是第一列的数据。环也缺少{
大括号}
。
移动线条
data = (uint8*)buf;
列循环外部,并在循环内递增。
for (row = 0; row < imagelength; row++)
{
TIFFReadScanline(tif, buf, row,1);
count2++;
data = (uint8*)buf; // move up
for (col = 0; col < scanline; col++)
{ // add braces
printf("%d ", *data);
im[count] = *data;
count++;
data++; // increment buffer pointer
}
printf("n");
}