Re: Image[], Graphics[Raster[]]

*To*: mathgroup at smc.vnet.net*Subject*: [mg100284] Re: Image[], Graphics[Raster[]]*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Sun, 31 May 2009 06:33:01 -0400 (EDT)*References*: <6147782.1243412890107.JavaMail.root@n11> <200905280829.EAA14200@smc.vnet.net> <gvqpu5$ck0$1@smc.vnet.net>

Hi, > > 1. Is Image[] any different than Graphics[Raster[]] that I'm more > accustomed to? No it has a fixed data range, i.e., "Byte" is [0,255], "Real" [0,1] while Graphics[Raster[]] can handle undestructive every thing. > > 2. If not, what was the point of introducing Image[]? Was it any effort to > provide a more streamlined set of commands all revolving around Image[], > e.g., ImageRotate[], etc.? The reason was a faster display of the bitmap. With fixed data range the FE don't have to do a scaling of every pixel. > > > 3. Image[] somehow upsets my unified view of Mathematica. That is, I like > to try to "think" like Mathematica, and so I understand that all commands > like Plot[], ListPlot[], etc., reduce to a Graphics[] object in > FullForm[]. Similarly, I can build my own type of plotting function with > Graphics[]. Most importantly, I can combine many different types of > objects into a single Graphics[]. Am I correct that Image[] represents > then a completely new display object? If so, is there a way, for example, > to have an Image[] and then draw across it with an Epilog rule like you > can do with Graphics[]? It seems a major setback if Image[] and Graphics[] > cannot be readily mixed. > Oh mixing is easy: img = Import["http://www.stephenwolfram.com/img/home/sw-portrait.jpg";] Graphics[ {Image`ToGraphicsRaster[img][[1]], Circle[{110.5, 110.5}, 10]}] draw a circle on the image. > Anyone out there to make the case that Image[] represents an important new > capability? No, it make many things more complicated, and a lot of image processing tasks impossible -- registration for example .. I see it as a little worse than the usual "new command that > does same thing old stuff did" because it seems to lose the capability to > mix Graphics[] and Image[]. > > Please inform me if I'm completely off base. As I said, I'm just digging > into Image[] now for the first time, and I'm a bit confused about possible > merits---please do inform! There is no merit, it make many things worse than the original Graphics[Raster[]] Regards Jens

**References**:**Re: new to group - Chemical Equation Solutions***From:*"David Park" <djmpark@comcast.net>