Why is bmp created as not transparent? - c++

Question

I have following code which creates transparent bmp image and saves it to clipboard. After this I tried to copy this to Photoshop or office, Gimp. But image is not transparent:
#include <Windows.h>
#include <iostream>
#include <Wingdi.h>
#include <algorithm>
using namespace std;
pair<int, HGLOBAL> dibv5_img(void)
{
const DWORD width = 100;
const DWORD height = 100;
BITMAPV5HEADER header = {0};
header.bV5Size = sizeof(BITMAPV5HEADER);
header.bV5Width = width;
header.bV5Height = -height;
header.bV5Planes = 1;
header.bV5BitCount = 32;
header.bV5Compression = BI_BITFIELDS;
header.bV5SizeImage = header.bV5Width * header.bV5Height * header.bV5BitCount / 8;
header.bV5CSType = LCS_WINDOWS_COLOR_SPACE;
header.bV5Intent = LCS_GM_IMAGES;
header.bV5BlueMask = 0x000000FF;
header.bV5GreenMask = 0x0000FF00;
header.bV5RedMask = 0x00FF0000;
header.bV5AlphaMask = 0xFF000000;
DWORD masks[3];
masks[0] = header.bV5BlueMask;
masks[1] = header.bV5GreenMask;
masks[2] = header.bV5AlphaMask;
DWORD pixels[width * height];
for (DWORD i = 0; i < height; ++i)
for (DWORD j = 0; j < width; ++j)
pixels[i * width + j] = 0;
for (DWORD i = height / 4; i < 3 * height / 4; ++i)
for (DWORD j = 0; j < width; ++j)
pixels[i * width + j] = (masks[0] | header.bV5AlphaMask) & 0xFFFFFFFF;
HGLOBAL hmem = GlobalAlloc(GHND | GMEM_DDESHARE, header.bV5Size + sizeof(DWORD) * (3 + width * height));
PVOID local_pointer = GlobalLock(hmem);
memcpy(local_pointer, &header, sizeof(BITMAPV5HEADER));
memcpy(reinterpret_cast<unsigned char*>(local_pointer) + sizeof(BITMAPV5HEADER), masks, sizeof(DWORD) * 3);
memcpy(reinterpret_cast<unsigned char*>(local_pointer) + sizeof(BITMAPV5HEADER) + sizeof(DWORD) * 3, pixels,
sizeof(DWORD) * width * height);
GlobalUnlock(hmem);
return pair<int, HGLOBAL>(CF_DIBV5, hmem);
}
int main(void)
{
cout << sizeof(DWORD) << endl;
if (!OpenClipboard(0))
return 1;
if (!EmptyClipboard())
return 1;
const auto data = dibv5_img();
SetClipboardData(data.first, data.second);
if (!CloseClipboard())
return 1;
return 0;
}
Output in all apps is following: