iphone - Compress Large UIImage -

so im doing compressing image repeatedly until fits within size frame. it takes many attempts, give , later tell user image large.

my issue after image size has been reduced, size goes way again when changed uiimage.

here code reducing image size:

    double compressionratio = 1;     int resizeattempts = 5;      nsdata * imgdata = uiimagejpegrepresentation([info objectforkey:@"uiimagepickercontrolleroriginalimage"],compressionratio);      nslog(@"starting size: %i", [imgdata length]);      //trying push below around 0.4 meg     while ([imgdata length] > 400000 && resizeattempts > 0) {         resizeattempts -= 1;          nslog(@"image bigger 400000 bytes. resizing.");         nslog(@"%i attempts remaining",resizeattempts);          //increase compression amount         compressionratio = compressionratio*0.5;          //test size before compression         nslog(@"current size: %i",[imgdata length]);         imgdata = uiimagejpegrepresentation([info objectforkey:@"uiimagepickercontrolleroriginalimage"],compressionratio);          //test size after compression         nslog(@"new size: %i",[imgdata length]);     }      //set image comprssed version     savedimage = [uiimage imagewithdata:imgdata];      //check how big image been compressed , put uiimageview     nsdata *enddata = uiimagejpegrepresentation(savedimage,1.0);     nslog(@"ending size: %i", [enddata length]); 

ok here console report:

starting image size: 4076994  image bigger 400000 bytes. resizing. 4 attempts remaining current size: 4076994 new compressed size: 844482  image bigger 400000 bytes. resizing. 3 attempts remaining current size: 844482 new compressed size: 357459  ending image size: 2090332 

as can see image started @ 4mb big. compressed 350kb, in end made uiimage 2mb.

thanks in advance can make sense of this.

i have modified function bit , got result, try it, reduce 10mb image 3mb.

-(void)compraseimage {     uiimage *largeimage = [info objectforkey:@"uiimagepickercontrolleroriginalimage"];      double compressionratio = 1;     int resizeattempts = 5;      nsdata * imgdata = uiimagejpegrepresentation(largeimage,compressionratio);      nslog(@"starting size: %i", [imgdata length]);      //trying push below around 0.4 meg     while ([imgdata length] > 400000 && resizeattempts > 0) {         resizeattempts -= 1;          nslog(@"image bigger 400000 bytes. resizing.");         nslog(@"%i attempts remaining",resizeattempts);          //increase compression amount         compressionratio = compressionratio*0.5;         nslog(@"compressionratio %f",compressionratio);         //test size before compression         nslog(@"current size: %i",[imgdata length]);         imgdata = uiimagejpegrepresentation(largeimage,compressionratio);          //test size after compression         nslog(@"new size: %i",[imgdata length]);     }      //set image comprssed version     savedimage = [uiimage imagewithdata:imgdata];      //check how big image been compressed , put uiimageview      // *** made change here, again storing highest resolution ***     nsdata *enddata = uiimagejpegrepresentation(largeimage,compressionratio);     nslog(@"ending size: %i", [enddata length]);      nsstring *path = [self createpath:@"myimage.jpg"];     nslog(@"%@",path);     [enddata writetofile:path atomically:yes]; }  -(nsstring *) createpath:(nsstring *)withfilename {     nsarray *paths =nssearchpathfordirectoriesindomains(nsdocumentdirectory,nsuserdomainmask,                                                         yes);     nsstring *documentsdirectory = [paths objectatindex:0];     nsstring *path = [documentsdirectory stringbyappendingpathcomponent:withfilename];     return path; }