Can I convert a BaseBitmap into a Image file in memory?

Dunhou

Hi community !

I want to send my render images to a website, but I have to use BaseBitmap.Save to save the result and then post them, I am trying to speed this a little, and I didn't know to can I do this :

convert the BaseBitmap to a "normal" PNG image file in memory.
send the file to a server directly without write them to disk.

Is that possible to do this？

Cheers~
DunHou

ferdinand

Hey @Dunhou,

Thank you for reaching out to us. I am a bit surprised that you ask since we recently had this thread and you liked it, so you must have seen it, but here you go. I did not double check if the MFS byte content is actually identical to a file on disk, but it should be.

Cheers,
Ferdinand

"""Implements a Cinema 4D python script that generates a gradient bitmap and writes it to a file
in memory, and then prints the memory struct data to the console and displays the bitmap in the
Cinema 4D picture viewer.
"""

import c4d
import http.client
import itertools

from mxutils import CheckType, CheckIterable

def CreateTexture(size: tuple[int, int]) -> c4d.bitmaps.BaseBitmap:
    """Creates a new texture with the given size and fills it with a gradient.
    """
    CheckIterable(size, int, tuple, minCount=2, maxCount=2)
    bmp: c4d.bitmaps.BaseBitmap = CheckType(c4d.bitmaps.BaseBitmap())
    if bmp.Init(size[0], size[1]) != c4d.IMAGERESULT_OK:
        raise RuntimeError("Failed to initialize bitmap.")

    for x, y in itertools.product(range(size[0]), range(size[1])):
        color: c4d.Vector = c4d.Vector(x / size[0], y / size[1], 0)
        bmp.SetPixel(x, y, int(color.x * 254.99), int(color.y * 254.99), int(color.z * 254.99))
    
    return bmp

def main():
    """
    """
    bmp: c4d.bitmaps.BaseBitmap = CreateTexture((256, 256))
    mfs: c4d.storage.MemoryFileStruct = c4d.storage.MemoryFileStruct()
    mfs.SetMemoryWriteMode()

    if bmp.Save(mfs, c4d.FILTER_PNG) != c4d.IMAGERESULT_OK:
        raise RuntimeError("Failed to save bitmap to memory file.")
    
    data: bytearray # The data of the memory file struct.
    size: int # The size of the data in the memory file struct in bytes.
    data, size = mfs.GetData()

    # Send the data to an endpoint using a POST request.
    # client: http.client.HTTPConnection = http.client.HTTPConnection("https://foo.net", 80)
    # if client.connect():
    #     client.request("POST", "/endpoint", body=data)
    #     response: http.client.HTTPResponse = client.getresponse()
    #     print (response.status, response.reason)

    # Print a hex dump of the first 32 bytes of the data in blocks of 8 bytes.
    print("Data: ")
    for i in range(0, 32, 8):
        print(" ".join(f"{b:02X}" for b in data[i:i+8]))

    c4d.bitmaps.ShowBitmap(bmp)

if __name__=='__main__':
    main()

edit: On a quick check, the output seems good:

https://en.wikipedia.org/wiki/List_of_file_signatures

Dunhou

Hey @ferdinand , oops, I have an impression of this topic and tried to recall it, but I couldn't find any keywords in my mind at the time. I must have gone crazy.

And the key is the GetData(), I have no concept of file composition and did not realize that what is returned here is the data required for an image file. Thank you very much.

Cheers~
DunHou