[ENH] Faster BMP writing
Yoshiki Ohshima
Yoshiki.Ohshima at acm.org
Thu Feb 19 02:40:54 UTC 2004
Hello,
Lately, I'm generating thousands of BMP files.
It seems that there was some attempt to make a primitive for it, but
the one in the VMMaker doesn't seem to be complete and the primitive
only handles depth=32 Forms, which doesn't serve my purpose because
the BMP I'm interested in happens to be 8 bit.
So, I did a little hack to speed up the BMP writing. With this
changeset, writing a 720x480x8 Form to a byte array as BMP becomes 30
times faster.
-----------------
f _ Form extent: 720 at 480 depth: 8.
bytes _ ByteArray new: 500000.
[100 timesRepeat: [
w _ WriteStream on: bytes.
b _ BMPReadWriter on: w.
b nextPutImage: f.
]] timeToRun.
-----------------
This changeset factors out the depth=32 case. Presumably, it should
make it easier to adapt the BMP writing primitive.
-- Yoshiki
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