Hi List,
I know how to calculate the amount of memory an image takes:
img.width * img.height * img.depth / 8
If I import a 24-bit image, the resulting cast member is 32 bit.
Or if I create an image in 24 bit color depth:
img = image(width, height, 24)
img.depth always gives 32.
Maybe it's
Hi Michael,
I would guess that this has to do with how each pixel is represented. On a 32-bit
architecture, each integer can be divided into pixels a number of ways neatly: four
8-bit pixels, two 16-bit pixels, one 32-bit pixel. To span a pixel across integers
would be inefficient. So for
On a different, but related note, try using 1-bit members versus 32-bit.
1-bit will animate slower than 32-bit, even though it is 32 times as small.
Really? I've been using 1-bit bitmaps for my text highlighter, with the belief
that I can resize and reposition them more quickly and reliably
Hi Kerry,
It's definitely an issue. In one project, I have a white and black bitmap covering
the entire stage (and it's a large stage, matching the monitor up to 1400X1050). It
is dynamically rendered to connect different elements of a visual data structure. At
1-bit, it was totally
The problem with one-bit stuff is getting that bit out of there. You have
to break apart a byte to get at each bit and it's a hassle with code. It
keeps the image size down, sure, but it's not fast.
You'd be much better off going with 256-color images. Still enough color
to do most artwork,
32-bit would be fastest from the point of view of
accessing (quickest to access a 32-bit offset) but it's a pig when it comes
to space.
Thanks Tab and all who answered. The 1-bit, 8-bit or 16-bit solutions don't
interest me, because my images are and have to be 24-bit.
Can anybody please
It's definitely an issue. At 1-bit, it was totally
unnacceptable, even on a fast machine. At 8-bits, it plays fine.
For my text highlighter, I use QuickDraw rectangles.
Thanks. I've used vectors for text highlighting, too. This was an inherited
project, and the outgoing engineer insisted
Can anybody please confirm that 24-bit images always take up the same memory
space as 32-bit images?
One word: alpha.
There really is no such thing as 32-bit color, at least in common useage. A 32-
bit image has 24 bits for color, and 8 bits for the alpha channel. I think
Director keeps that
