libqrencode如何自定义二维码生成图片的尺寸 C++

[nslh520]

各位大神：
请问 libqrencode如何自定义二维码生成图片尺寸 C++ ?先谢了

官网实例如下：

char* szSourceSring = "1255335584";
unsigned int unWidth, x, y, l, n, unWidthAdjusted, unDataBytes;
unsigned char* pRGBData, *pSourceData, *pDestData;
QRcode* pQRC;
FILE* f;

if (pQRC = QRcode_encodeString(szSourceSring, 0, QR_ECLEVEL_H, QR_MODE_8, 1))
{
unWidth = pQRC->width;
unWidthAdjusted = unWidth * 8 * 3;
if (unWidthAdjusted % 4)
unWidthAdjusted = (unWidthAdjusted / 4 + 1) * 4;
unDataBytes = unWidthAdjusted * unWidth * 8;

// Allocate pixels buffer

if (!(pRGBData = (unsigned char*)malloc(unDataBytes)))
{
exit(-1);
}

// Preset to white

memset(pRGBData, 0xff, unDataBytes);


// Prepare bmp headers

BITMAPFILEHEADER kFileHeader;
kFileHeader.bfType = 0x4d42; // "BM"
kFileHeader.bfSize = sizeof(BITMAPFILEHEADER) +
sizeof(BITMAPINFOHEADER) +
unDataBytes;
kFileHeader.bfReserved1 = 0;
kFileHeader.bfReserved2 = 0;
kFileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) +
sizeof(BITMAPINFOHEADER);

BITMAPINFOHEADER kInfoHeader;
kInfoHeader.biSize = sizeof(BITMAPINFOHEADER);
kInfoHeader.biWidth = unWidth * 8;
kInfoHeader.biHeight = -((int)unWidth * 8);
kInfoHeader.biPlanes = 1;
kInfoHeader.biBitCount = 24;
kInfoHeader.biCompression = BI_RGB;
kInfoHeader.biSizeImage = 0;
kInfoHeader.biXPelsPerMeter = 0;
kInfoHeader.biYPelsPerMeter = 0;
kInfoHeader.biClrUsed = 0;
kInfoHeader.biClrImportant = 0;


// Convert QrCode bits to bmp pixels

pSourceData = pQRC->data;
for (y = 0; y < unWidth; y++)
{
pDestData = pRGBData + unWidthAdjusted * y * 8;
for (x = 0; x < unWidth; x++)
{
if (*pSourceData & 1)
{
for (l = 0; l < 8; l++)
{
for (n = 0; n < 8; n++)
{
*(pDestData + n * 3 + unWidthAdjusted * l) = 0xff;
*(pDestData + 1 + n * 3 + unWidthAdjusted * l) = 0;
*(pDestData + 2 + n * 3 + unWidthAdjusted * l) = 0;
}
}
}
pDestData += 3 * 8;
pSourceData++;
}
}


// Output the bmp file

if (!(fopen_s(&f, "temp.bmp", "wb")))
{
fwrite(&kFileHeader, sizeof(BITMAPFILEHEADER), 1, f);
fwrite(&kInfoHeader, sizeof(BITMAPINFOHEADER), 1, f);
fwrite(pRGBData, sizeof(unsigned char), unDataBytes, f);

fclose(f);
}
else
{
printf("Unable to open file");
exit(-1);
}

// Free data

free(pRGBData);
QRcode_free(pQRC);
}
else
{
printf("NULL returned");
exit(-1);
}

[赵4老师]

将生成的图片缩放到自己需要的大小。