cocoa - Converting between multiple image formats in Objective-C -

i want able to, being given path image, convert image image, different format. format mean .png, .bmp .jpg .tiff, etc. in pseudocode, easy:

image = [imageapi open: imagepath] [image save: imagepath withformat: imageformat] // important 

i have no idea how this, though. barely know more nsimage class when comes handling images), , not seem have answer problem (no simple save methods this). here list of formats i'd support:

• .png
• .tiff
• .gif
• .jpeg
• .bmp
• probably .pdf (if isn't complicated)

by support mean opening of , saving opened image of formats. there combinations here (15 ??? - think), write method each combination so:

[self savetiffimageintogifwithpath: path] (*15 !!!) 

but defenitely better use apis.

if chance along way have options like:

• keep alpha or not
• resize images

...i'd happy support them well, although they're optional. hope there's simple way this. thanks

ps: know there have been questions topic, iphone oriented (i want on mac) , none of them provided way multiple formats.

allright, peter's figure out. first, if you're working image paths, open directly file nsdata so:

nsdata* imgdata = [nsdata datawithcontentsoffile: filepath]; 

if you're working nsimage objects , difficult have path (for example nsimageview) (image nsimage object have):

nsdata* imgdata = [image tiffrepresentation]; 

now have image nsdata objects, nsbitmapimagerep:

nsbitmapimagerep* bitmap = [nsbitmapimagerep imagerepwithdata: imgdata]; 

and new nsdata object, different format:

nsdata* newdata = [bitmap representationusingtype: nspngfiletype properties: nil]; // used nspngfiletype example, // types wanted convert between (except pdf) supported 

finally, save newdata file:

[newdata writetofile: newpath atomically: yes] 

simple pie, once how works!

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the support transparency , size control not difficult either:

• the nsimage class provides support setting image's size (-setsize:)
• the nsimagerep (superclass of nsbitmapimagerep) has -setalpha: method

just call when need. +1 cocoa!