Re: Precise bitmaps
- To: mathgroup at smc.vnet.net
- Subject: [mg96720] Re: Precise bitmaps
- From: ragfield <ragfield at gmail.com>
- Date: Sun, 22 Feb 2009 03:11:55 -0500 (EST)
- References: <gnq6ni$83g$1@smc.vnet.net>
On Feb 21, 6:37 pm, "Diamond, Mark" <d... at dot.dot> wrote:
> A question was asked back in 2005 about precise bitmaps. I have a similar
> question with regard to Mathematica version 7.
>
> Looking at the new image-manipulation functions in V7, I expected this to=
be
> quick ... I'd like to be able to create a series of stimuli for use in an
> experiment. The first step in creating the stimuli is to create a 512 x 5=
12
> greyscale image with a white background and which contains the drawn
> objects.
>
> I tried the following to create a JPEG image with dimensions 128x128 ...
>
> circ=Graphics[Circle[{0,0},62]]
> rasterCirc=Rasterize[circ,RasterSize->{128,128}]
> Export["circle.jpg",rasterCirc]
>
> but instead the image dimensions are 360 x 363 pixels. I had also hoped t=
hat
> I could obtain an antialiased arc but the only antialiasing option seems =
to
> be for Style, which then produces a non-Graphics object.
>
> Can anyone see a simple (i.e., not very low-level programming) solution t=
o
> the problem within Mathematica? What have I missed conceptually that woul=
d
> explain the 360x363 pixel dimensions instead of my expected 128x128? And =
is
> there a way to obtain the anti-aliased circle?
circ = Graphics[Circle[{0, 0}, 62], ImageSize -> 128]
rasterCirc = Rasterize[circ] (* this step is not strictly necessary *)
Export["circle.jpg",rasterCirc]
-Rob