原图：
效果图：
实现：
首先需要导入accelerate.framework。
然后把两个文件加入到自己的项目中即可。
uiimage+imageeffects.h
#import
@interfaceuiimage(imageeffects)
-(uiimage*)applylighteffect;
-(uiimage*)applyextralighteffect;
-(uiimage*)applydarkeffect;
-(uiimage*)applytinteffectwithcolor:(uicolor*)tintcolor;
-(uiimage*)applyblurwithradius:(cgfloat)blurradius tintcolor:(uicolor*)tintcolor saturationdeltafactor:(cgfloat)saturationdeltafactor maskimage:(uiimage*)maskimage;
@end
uiimage+imageeffects.m
#import "uiimage+imageeffects.h"
#import
#import
@implementationuiimage(imageeffects)
-(uiimage*)applylighteffect
{
uicolor*tintcolor =[uicolor colorwithwhite:1.0 alpha:0.3];
return[self applyblurwithradius:30 tintcolor:tintcolor saturationdeltafactor:1.8 maskimage:nil];
}
-(uiimage*)applyextralighteffect
{
uicolor*tintcolor =[uicolor colorwithwhite:0.97 alpha:0.82];
return[self applyblurwithradius:20 tintcolor:tintcolor saturationdeltafactor:1.8 maskimage:nil];
}
-(uiimage*)applydarkeffect
{
uicolor*tintcolor =[uicolor colorwithwhite:0.11 alpha:0.73];
return[self applyblurwithradius:20 tintcolor:tintcolor saturationdeltafactor:1.8 maskimage:nil];
}
-(uiimage*)applytinteffectwithcolor:(uicolor*)tintcolor
{
constcgfloateffectcoloralpha=0.6;
uicolor*effectcolor = tintcolor;
int componentcount =cgcolorgetnumberofcomponents(tintcolor.cgcolor);
if(componentcount ==2){
cgfloat b;
if([tintcolor getwhite:&b alpha:null]){
effectcolor =[uicolor colorwithwhite:b alpha:effectcoloralpha];
}
}
else{
cgfloat r, g, b;
if([tintcolor getred:&r green:&g blue:&b alpha:null]){
effectcolor =[uicolor colorwithred:r green:g blue:b alpha:effectcoloralpha];
}
}
return[self applyblurwithradius:10 tintcolor:effectcolor saturationdeltafactor:-1.0 maskimage:nil];
}
-(uiimage*)applyblurwithradius:(cgfloat)blurradius tintcolor:(uicolor*)tintcolor saturationdeltafactor:(cgfloat)saturationdeltafactor maskimage:(uiimage*)maskimage
{
// check pre-conditions.
if(self.size.width <1||self.size.height <1){
nslog(@"*** error: invalid size: (%.2f x %.2f). both dimensions must be >= 1: );
returnnil;
}
if(!self.cgimage){
nslog(@"*** error: image must be backed by a cgimage: );
returnnil;
}
if(maskimage &&!maskimage.cgimage){
nslog(@"*** error: maskimage must be backed by a cgimage: %@", maskimage);
returnnil;
}
cgrect imagerect ={cgpointzero,self.size };
uiimage*effectimage =self;
bool hasblur = blurradius > __flt_epsilon__;
bool hassaturationchange = fabs(saturationdeltafactor -1.)> __flt_epsilon__;
if(hasblur || hassaturationchange){
uigraphicsbeginimagecontextwithoptions(self.size, no,[[uiscreen mainscreen] scale]);
cgcontextref effectincontext =uigraphicsgetcurrentcontext();
cgcontextscalectm(effectincontext,1.0,-1.0);
cgcontexttranslatectm(effectincontext,0,-self.size.height);
cgcontextdrawimage(effectincontext, imagerect,self.cgimage);
vimage_buffer effectinbuffer;
effectinbuffer.data =cgbitmapcontextgetdata(effectincontext);
effectinbuffer.width =cgbitmapcontextgetwidth(effectincontext);
effectinbuffer.height =cgbitmapcontextgetheight(effectincontext);
effectinbuffer.rowbytes =cgbitmapcontextgetbytesperrow(effectincontext);
uigraphicsbeginimagecontextwithoptions(self.size, no,[[uiscreen mainscreen] scale]);
cgcontextref effectoutcontext =uigraphicsgetcurrentcontext();
vimage_buffer effectoutbuffer;
effectoutbuffer.data =cgbitmapcontextgetdata(effectoutcontext);
effectoutbuffer.width =cgbitmapcontextgetwidth(effectoutcontext);
effectoutbuffer.height =cgbitmapcontextgetheight(effectoutcontext);
effectoutbuffer.rowbytes =cgbitmapcontextgetbytesperrow(effectoutcontext);
if(hasblur){
// a description of how to compute the box kernel width from the gaussian
// radius (aka standard deviation) appears in the svg spec:
//
//
// for larger values of 's' (s >= 2.0), an approximation can be used: three
// successive box-blurs build a piece-wise quadratic convolution kernel, which
// approximates the gaussian kernel to within roughly 3%.
//
// let d = floor(s * 3*sqrt(2*pi)/4 + 0.5)
//
// ... if d is odd, use three box-blurs of size 'd', centered on the output pixel.
//
cgfloat inputradius = blurradius *[[uiscreen mainscreen] scale];
nsuinteger radius = floor(inputradius *3.* sqrt(2* m_pi)/4+0.5);
if(radius %2!=1){
radius +=1;// force radius to be odd so that the three box-blur methodology works.
}
vimageboxconvolve_argb8888(&effectinbuffer,&effectoutbuffer, null,0,0, radius, radius,0, kvimageedgeextend);
vimageboxconvolve_argb8888(&effectoutbuffer,&effectinbuffer, null,0,0, radius, radius,0, kvimageedgeextend);
vimageboxconvolve_argb8888(&effectinbuffer,&effectoutbuffer, null,0,0, radius, radius,0, kvimageedgeextend);
}
bool effectimagebuffersareswapped = no;
if(hassaturationchange){
cgfloat s = saturationdeltafactor;
cgfloat floatingpointsaturationmatrix[]={
0.0722+0.9278* s,0.0722-0.0722* s,0.0722-0.0722* s,0,
0.7152-0.7152* s,0.7152+0.2848* s,0.7152-0.7152* s,0,
0.2126-0.2126* s,0.2126-0.2126* s,0.2126+0.7873* s,0,
0,0,0,1,
};
constint32_t divisor =256;
nsuinteger matrixsize =sizeof(floatingpointsaturationmatrix)/sizeof(floatingpointsaturationmatrix[0]);
int16_t saturationmatrix[matrixsize];
for(nsuinteger i =0; i < matrixsize;++i){
saturationmatrix[i]=(int16_t)roundf(floatingpointsaturationmatrix[i]* divisor);
}
if(hasblur){
vimagematrixmultiply_argb8888(&effectoutbuffer,&effectinbuffer, saturationmatrix, divisor, null, null, kvimagenoflags);
effectimagebuffersareswapped = yes;
}
else{
vimagematrixmultiply_argb8888(&effectinbuffer,&effectoutbuffer, saturationmatrix, divisor, null, null, kvimagenoflags);
}
}
if(!effectimagebuffersareswapped)
effectimage =uigraphicsgetimagefromcurrentimagecontext();
uigraphicsendimagecontext();
if(effectimagebuffersareswapped)
effectimage =uigraphicsgetimagefromcurrentimagecontext();
uigraphicsendimagecontext();
}
// set up output context.
uigraphicsbeginimagecontextwithoptions(self.size, no,[[uiscreen mainscreen] scale]);
cgcontextref outputcontext =uigraphicsgetcurrentcontext();
cgcontextscalectm(outputcontext,1.0,-1.0);
cgcontexttranslatectm(outputcontext,0,-self.size.height);
// draw base image.
cgcontextdrawimage(outputcontext, imagerect,self.cgimage);
// draw effect image.
if(hasblur){
cgcontextsavegstate(outputcontext);
if(maskimage){
cgcontextcliptomask(outputcontext, imagerect, maskimage.cgimage);
}
cgcontextdrawimage(outputcontext, imagerect, effectimage.cgimage);
cgcontextrestoregstate(outputcontext);
}
// add in color tint.
if(tintcolor){
cgcontextsavegstate(outputcontext);
cgcontextsetfillcolorwithcolor(outputcontext, tintcolor.cgcolor);
cgcontextfillrect(outputcontext, imagerect);
cgcontextrestoregstate(outputcontext);
}
// output image is ready.
uiimage*outputimage =uigraphicsgetimagefromcurrentimagecontext();
uigraphicsendimagecontext();
return outputimage;
}
@end
调用：
uiimageview*me =[[uiimageview alloc] initwithframe:cgrectmake(10,480,614,381)];
[me setimage:[[uiimage imagenamed:@"me.png"] applyblurwithradius:5 tintcolor:[uicolor colorwithwhite:1 alpha:0.2] saturationdeltafactor:1.8 maskimage:nil]];
[self.view addsubview:me];
ok！so easy！
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