Set coordinate origin to the top left corner

Question

I have a BMP-picture and I know that it's top left corner has the EPSG:3068 coordinates 35500,24390. I would like to use gdal_polygonize and than calculate the EPSG:3068 coordinates of the produced polygons. But for that I need gdal_polygonize to assume that the top left corner is (0,0) or I need to know at which pixel the actual (0,0) is. gdalinfo of the picture:

Driver: BMP/MS Windows Device Independent Bitmap
Files: E8256.bmp
Size is 8250, 4090
Coordinate System is `'
Origin = (-1890.000000000000000,1890.000000000000000)
Pixel Size = (3780.000000000000000,-3780.000000000000000)
Corner Coordinates:
Upper Left  (   -1890.000,    1890.000)
Lower Left  (   -1890.000,-15458310.000)
Upper Right (31183110.000,    1890.000)
Lower Right (31183110.000,-15458310.000)
Center      (15590610.000,-7728210.000)
Band 1 Block=8250x1 Type=Byte, ColorInterp=Palette
  Color Table (RGB with 256 entries)
    0: 0,0,0,255
    1: 128,0,0,255
    ...

as you can see the top left corner is -1890,1890. I want that to become 0,0 OR to know at wich pixel 0,0 is. (Pixel size is the length of 1 pixel in coordinates right?)

Answer 1

I used gdal_translate -a_ullr 0 0 8250 4090 -of "BMP" source.bmp target.bmp which solved the problem.