Re: Image, Graphics[Raster]
- To: mathgroup at smc.vnet.net
- Subject: [mg100420] Re: Image, Graphics[Raster]
- From: lehin.p at gmail.com
- Date: Wed, 3 Jun 2009 01:10:27 -0400 (EDT)
- References: <6147782.1243412890107.JavaMail.root@n11> <200905280829.EAA14200@smc.vnet.net>
On 2 =C9=C0=CE, 14:46, Jens-Peer Kuska <ku... at informatik.uni-leipzig.de> wrote: > Hi, > > what do you want ? a solution to the problem or > a pointer to the documentation ? > Hello, First of all I would want to get a pointer to documentation where such functions as "Image`ToGraphicsRaster" and "Image`PossibleImageQ" are documented. Are there other such built-in functions? At this moment I even can't imagine from where I could learn that such functions exists... And recently I had an opposite problem: how to convert Graphics (that contain Raster) to Image without loosing quality. Why I need this? There are two reasons: 1) Graphics has a default width 360 pixels and in this way the quality will be only 360 pixels width even if Raster inside Graphics contains much more points. And resizing does not help. It also directly affects Export... :( But Image always has true dimensions and preserves quality. I discussed it in detail here: http://tinyurl.com/njmpro 2) I have not found a perfect way how to change *default* width of Graphics (without using ImageSize). I discussed it here: http://tinyurl.com/l288ne I have created a function Raster2Image that converts Graphics[Raster ] to Image with preserving quality (as opposed to Image[Graphics]): Raster2Image = Image[Part[#, Sequence @@ Position[#, _Raster] [], 1], ColorSpace -> "RGB"] &; But it is not so universal as I would want. May be there is an built- in alternative to this? Or you have more universal variant? I also created function fix4Graphics that fixes the above-mentioned behavior (loosing quality): fix4Graphics = Append[#, ImageSize -> Reverse[Take[Dimensions [Part[#, Sequence @@ Position[#, _Raster][], 1]], 2]]] &; But it is also faraway from universality. So I am interested in more universal solutions and knowledge about undocumented functions for working with graphics...