Re: Exporting a bitmap in native resolution

• To: mathgroup at smc.vnet.net
• Subject: [mg96682] Re: Exporting a bitmap in native resolution
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Fri, 20 Feb 2009 05:47:59 -0500 (EST)
• Organization: Uni Leipzig
• References: <gnj5jn\$iio\$1@smc.vnet.net>

```Hi,

take the data from the DensityGraphics
and use

ImageMatrixQ[bm_?MatrixQ] := True
ImageMatrixQ[bm_?(MatrixQ[#, VectorQ] &)] := True
ImageMatrixQ[_] := False

MatrixToImage[data_?ImageMatrixQ] :=
Module[{dim, ny, nx, ch, mind, maxd, colorf},
dim = Dimensions[data];
{ny, nx} = Take[dim, 2];
If[3==Length[dim],
ch = Last[dim],
ch = 1
];
colorf = Switch[ch,
1, GrayLevel,
2, GrayLevel,
3, RGBColor,
4, RGBColor
];
{mind, maxd} = {Min[#], Max[#]} &[Flatten[data]];
If[Sqrt[#.#]&[{mind,maxd}-Round[{mind,maxd}]]<\$MachineEpsilon,
{mind, maxd}=Round[{mind, maxd}]
];
If[Abs[maxd-mind]<\$MachineEpsilon,
maxd=mind+1
];
Graphics[
Raster[
Developer`ToPackedArray[data], {{0, 0}, {nx, ny}}, {mind, maxd},
ColorFunction -> colorf
], AspectRatio -> Automatic,
PlotRange -> {{0, nx}, {0, ny}}, ImageSize -> {nx, ny}
]
]

the MatrixToImage[] function above.

Regards
Jens

sibir wrote:
> HI all,
> first I must mention that I am still on 5.2, but I suspect the problem
> is universal. I have a ListDensityPlot which I want to export as a
> bitmap (e.g., png) in native resolution, that is each data point
> yielding one pixel.
> I tried ImageSize and ImageResolution and googled around to no avail.
> Anybody figured out how to do that?
>
> Thanks, Martin
>

```

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