我想按“n”调整它的大小,它适用于某些图像,但不适用于其他图像,我不知道为什么,据我所知,它没有图像特定的代码,它应该适用于每个图像
// Get multiplier
int n = atoi(argv[1]);
// read infile's BITMAPFILEHEADER
BITMAPFILEHEADER bf,bfR;
fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);
bfR = bf;
// read infile's BITMAPINFOHEADER
BITMAPINFOHEADER bi,biR;
fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);
biR = bi;
// ensure infile is (likely) a 24-bit uncompressed BMP 4.0
if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 ||
bi.biBitCount != 24 || bi.biCompression != 0)
{
fclose(outptr);
fclose(inptr);
fprintf(stderr, "Unsupported file format.\n");
return 4;
}
// modify bitmapinfoheader for height an width
biR.biWidth = bi.biWidth*n;
biR.biHeight = bi.biHeight*n;
// determine padding for scanlines
int padding = (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
int outpadding = (4 - (biR.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
// modify bisizeimage
biR.biSizeImage = (((biR.biWidth*(sizeof(RGBTRIPLE)))+outpadding)*abs(biR.biHeight));
// write outfile's BITMAPFILEHEADER
fwrite(&bfR, sizeof(BITMAPFILEHEADER), 1, outptr);
// modify bfsize before writing it
bfR.bfSize = (sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + sizeof(biR.biSizeImage));
// write outfile's BITMAPINFOHEADER
fwrite(&biR, sizeof(BITMAPINFOHEADER), 1, outptr);
// iterate over infile's scanlines
for (int i = 0, biHeight = abs(bi.biHeight); i < biHeight; i++)
{
for(int m = 0; m < n; m++)
{
// iterate over pixels in scanline
for (int j = 0; j < bi.biWidth; j++)
{
// temporary storage
RGBTRIPLE triple;
// read RGB triple from infile
fread(&triple, sizeof(RGBTRIPLE), 1, inptr);
// write RGB triple to outfile
for (int k = 0; k < n; k++)
{
fwrite(&triple, sizeof(RGBTRIPLE), 1, outptr);
}
}
// skip over padding, if any
fseek(inptr, padding, SEEK_CUR);
//go back to reprint the same line
if(m != n-1)
{
fseek(inptr, -bi.biWidth * sizeof(RGBTRIPLE),SEEK_CUR);
}
// then add it back (to demonstrate how)
for (int k = 0; k < padding; k++)
{
fputc(0x00, outptr);
}
任何人都可以告诉我问题所在吗?我尝试在网上查找,但找不到任何解决方案。网站上显示“看起来您的帖子主要是代码;请添加更多详细信息”,我应该写更多内容......
问题是由于填充的实现方式造成的。