UIImage的各種處理(旋轉(zhuǎn),壓縮,寫入,讀去,計算大小)等和方法的區(qū)別的介紹
第一:UIImage的詳細使用。
//
//? Image_Do_ViewController.m
//? UIImage_處理
//
//? Created by周雙建on 16/4/12.
//? Copyright ? 2016年周雙建. All rights reserved.
//
#import"Image_Do_ViewController.h"
#define APP_Width ? ? [UIScreen mainScreen].bounds.size.width
#define APP_Height? ? [UIScreen mainScreen].bounds.size.height
@interfaceImage_Do_ViewController()
@property(nonatomic,strong)UIImageView* IM_View;
@end
@implementationImage_Do_ViewController
- (void)viewDidLoad {
[superviewDidLoad];
self.navigationController.navigationBarHidden=NO;
self.navigationController.navigationBar.translucent=NO;
self.view.backgroundColor= [[UIColorwhiteColor]colorWithAlphaComponent:1.0f];
self.title=@"Succes QQ Bar-Provide";
[self.navigationController.navigationBarsetTitleTextAttributes:@{NSFontAttributeName:[UIFontfontWithName:@"Zapfino"size:20],NSForegroundColorAttributeName:[[UIColorblueColor]colorWithAlphaComponent:0.78f]}];
#pragma ImageDO
[selfImageLoad];
//[self ImageLoad];
// Do any additional setup after loading the view.
}
-(void)ImageLoad{
self.IM_View= [[UIImageViewalloc]initWithFrame:CGRectMake(20,20,APP_Width-40,APP_Height-104)];
self.IM_View.contentMode=UIViewContentModeScaleAspectFit;
/*
*這樣加載會造成圖片緩存
*? self.IM_View.image = [UIImage imageNamed:@"zsj.jpg"];
*
*? 1)用imageNamed的方式加載時,系統(tǒng)會把圖像Cache到內(nèi)存。如果圖像比較大,或者圖像比較多,用這種方式會消耗很大的內(nèi)存,而且釋放圖像的內(nèi)存是一件相對來說比較麻煩的事情。例如:如果利用imageNamed的方式加載圖像到一個動態(tài)數(shù)組NSMutableArray,然后將將數(shù)組賦予一個UIView的對象的animationImages進行逐幀動畫,那么這將會很有可能造成內(nèi)存泄露。并且釋放圖像所占據(jù)的內(nèi)存也不會那么簡單。但是利用imageNamed加載圖像也有自己的優(yōu)勢。對于同一個圖像系統(tǒng)只會把它Cache到內(nèi)存一次,這對于圖像的重復(fù)利用是非常有優(yōu)勢的。例如:你需要在一個TableView里重復(fù)加載同樣一個圖標,那么用imageNamed加載圖像,系統(tǒng)會把那個圖標Cache到內(nèi)存,在Table里每次利用那個圖像的時候,只會把圖片指針指向同一塊內(nèi)存。這種情況使用imageNamed加載圖像就會變得非常有效。
*/
//self.IM_View.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle]? pathForResource:@"zsj" ofType:@"jpg"]];
/*
*另一種加載方式,不進行圖片的緩存
*
*? ? self.IM_View.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle]? ? pathForResource:@"zsj" ofType:@"jpg"]];
*僅加載圖片,圖像數(shù)據(jù)不會緩存。因此對于較大的圖片以及使用情況較少時,那就可以用該方法,降低內(nèi)存消耗。
*/
/*
* ? self.IM_View.image = [UIImage imageWithData:[NSData dataWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"zsj" ofType:@"jpg"]]];
*
* ? 3)利用NSData方式加載時,圖像會被系統(tǒng)以數(shù)據(jù)方式加載到程序。當(dāng)你不需要重用該圖像,或者你需要將圖像以數(shù)據(jù)方式存儲到數(shù)據(jù)庫,又或者你要通過網(wǎng)絡(luò)下載一個很大的圖像時,請盡量使用imageWithData的方式加載圖像。
*
*/
/*********************************************************************************/
NSLog(@"W:%f ----H: %f",self.IM_View.image.size.width,self.IM_View.image.size.height);
UIImage* MY = [UIImageimageWithData:[NSDatadataWithContentsOfFile:[[NSBundlemainBundle]pathForResource:@"zsj"ofType:@"jpg"]]scale:0.5];
NSLog(@"M_W:%f ----M_H: %f",MY.size.width,MY.size.height);
/*
*
* scale為0.5的輸出
*
2016-04-14 09:29:00.896 UIImage_處理[880:25088] W:500.000000 ----H: 379.000000
2016-04-14 09:29:00.896 UIImage_處理[880:25088] M_W:1000.000000 ----M_H: 758.000000
*
*
* scale為2的輸出
2016-04-14 09:25:59.338 UIImage_處理[838:23420] W:500.000000 ----H: 379.000000
2016-04-14 09:25:59.338 UIImage_處理[838:23420] M_W:250.000000 ----M_H: 189.500000
*/
/*
*+ (nullable UIImage *)imageWithData:(NSData *)data scale:(CGFloat)scale NS_AVAILABLE_IOS(6_0);
*
*? @scale參數(shù)的說明
*? scale為小于零的數(shù)值(數(shù)值為A)的時候,image的大小(size)是按(1/A)增加的,增加后的大小是:size *(1/A)。
*? scale為大于零的數(shù)值(數(shù)值為A)的時候,image的大小(size)是按(1/A)減小的,減小后的大小是:size *(1/A)。
*/
/*********************************************************************************/
//將圖片轉(zhuǎn)化為二進制流
NSData* ImageData =UIImagePNGRepresentation(MY);
/*
* ? UIImagePNGRepresentation(UIImage * __nonnull image);
* ? return image as PNG. May return nil if image has no CGImageRef or invalid bitmap format
*/
NSData* ImageData1 =UIImageJPEGRepresentation(MY,1.0f);
/*
*? return image as JPEG. May return nil if image has no CGImageRef or invalid bitmap format. compression is 0(most)..1(least)
*/
/*
UIImagePNGRepresentation? |? UIImageJPEGRepresentation兩個的區(qū)別
UIImageJPEGRepresentation函數(shù)需要兩個參數(shù):圖片的引用和壓縮系數(shù).而UIImagePNGRepresentation只需要圖片引用作為參數(shù).通過在實際使用過程中,比較發(fā)現(xiàn): UIImagePNGRepresentation(UIImage* image)要比UIImageJPEGRepresentation(UIImage* image, 1.0)返回的圖片數(shù)據(jù)量大很多.譬如,同樣是讀取攝像頭拍攝的同樣景色的照片, UIImagePNGRepresentation()返回的數(shù)據(jù)量大小為199K ,而UIImageJPEGRepresentation(UIImage* image, 1.0)返回的數(shù)據(jù)量大小只為140KB,比前者少了50多KB.如果對圖片的清晰度要求不高,還可以通過設(shè)置UIImageJPEGRepresentation函數(shù)的第二個參數(shù),大幅度降低圖片數(shù)據(jù)量.譬如,剛才拍攝的圖片,通過調(diào)用UIImageJPEGRepresentation(UIImage* image, 1.0)讀取數(shù)據(jù)時,返回的數(shù)據(jù)大小為140KB,但更改壓縮系數(shù)后,通過調(diào)用UIImageJPEGRepresentation(UIImage* image, 0.5)讀取數(shù)據(jù)時,返回的數(shù)據(jù)大小只有11KB多,大大壓縮了圖片的數(shù)據(jù)量,而且從視角角度看,圖片的質(zhì)量并沒有明顯的降低.因此,在讀取圖片數(shù)據(jù)內(nèi)容時,建議優(yōu)先使用UIImageJPEGRepresentation,并可根據(jù)自己的實際使用場景,設(shè)置壓縮系數(shù),進一步降低圖片數(shù)據(jù)量大小.
*/
/*********************************************************************************/
//將圖片寫入文件
NSData* ImageData_W =UIImageJPEGRepresentation(MY,0.5f);
//獲取系統(tǒng)沙河路徑
NSArray* ArrayPath =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
NSString* path = [ArrayPathobjectAtIndex:0];
//開始寫入路徑的拼接
NSString* filePath = [pathstringByAppendingString:@"Image.text"];
//寫入
BOOLSucces = ? [ImageData_WwriteToFile:filePathatomically:YES];
NSLog(@"%d",Succes);
/*
輸出:UIImage_處理[1130:41357] 1寫入成功
*/
//將圖片從沙河讀取出來
NSString* ReadPath = filePath;
NSData* ReadData = [NSDatadataWithContentsOfFile:ReadPath];
UIImage* ReadImage = [UIImageimageWithData:ReadDatascale:2];
//self.IM_View.image = ReadImage;
/*********************************************************************************/
//改變圖像的方向
// self.IM_View.image = [UIImage imageWithCGImage:ReadImage.CGImage scale:1.0f orientation:UIImageOrientationLeftMirrored];
/*
*不用旋轉(zhuǎn)控件,來實現(xiàn)圖像的角度旋轉(zhuǎn)
typedef NS_ENUM(NSInteger, UIImageOrientation) {
UIImageOrientationUp,? ? ? ? ? ? // default orientation默認
UIImageOrientationDown,? ? ? ? ? // 180 deg rotation ? ? 180度的轉(zhuǎn)向
UIImageOrientationLeft,? ? ? ? ? // 90 deg CCW圖像逆時針90度
UIImageOrientationRight, ? ? ? ? // 90 deg CW圖像順時針90度
UIImageOrientationUpMirrored,? ? // as above but image mirrored along other axis. horizontal flip圖片的像素中間對稱水平翻轉(zhuǎn)
UIImageOrientationDownMirrored,? // horizontal flip圖片的像素中間對稱垂直翻轉(zhuǎn)
UIImageOrientationLeftMirrored,? // vertical flip圖片的像素左翻轉(zhuǎn)
UIImageOrientationRightMirrored, // vertical flip圖片的像素右翻轉(zhuǎn)
};
*/
/*********************************************************************************/
//用圖像獲取上下文
UIGraphicsBeginImageContext(ReadImage.size);//創(chuàng)建上下文
CGContextRefContextRef =UIGraphicsGetCurrentContext();//獲取上下文對象
CGContextSaveGState(ContextRef);//保存上下文,有利于還原場景
/*
*? [ReadImage drawInRect:CGRectMake(10, 10, 60, 60)];
*是在指定的大小范圍內(nèi)繪制圖片,圖片可完全繪出
*/
/*
*? [ReadImage drawAtPoint:CGPointMake(100, 100)];
*這個是不改變圖片的大小,是更改圖片的起始位置
*/
[ReadImagedrawInRect:CGRectMake(10,10,220,220)blendMode:kCGBlendModeSoftLightalpha:1.0f];
/*
*? - (void)drawInRect:(CGRect)rect blendMode:(CGBlendMode)blendMode alpha:(CGFloat)alpha;
typedef CF_ENUM (int32_t, CGBlendMode) {
kCGBlendModeNormal,正常;也是默認的模式。前景圖會覆蓋背景圖
kCGBlendModeMultiply,正片疊底;混合了前景和背景的顏色,最終顏色比原先的都暗
kCGBlendModeScreen,濾色;把前景和背景圖的顏色先反過來,然后混合
kCGBlendModeOverlay,覆蓋;能保留灰度信息,結(jié)合kCGBlendModeSaturation能保留透明度信息,在imageWithBlendMode方法中兩次執(zhí)行drawInRect方法實現(xiàn)我們基本需求
kCGBlendModeDarken,變暗
kCGBlendModeLighten,變亮
kCGBlendModeColorDodge,顏色變淡
kCGBlendModeColorBurn,顏色加深
kCGBlendModeSoftLight,柔光
kCGBlendModeHardLight,強光
kCGBlendModeDifference,插值
kCGBlendModeExclusion,排除
kCGBlendModeHue,色調(diào)
kCGBlendModeSaturation,飽和度
kCGBlendModeColor,顏色
kCGBlendModeLuminosity,亮度
kCGBlendModeClear,? ? ? ? ? ? ? ? ? ? R = 0清除所有的顏色
kCGBlendModeCopy, ? ? ? ? ? ? ? ? ? ? R = S
kCGBlendModeSourceIn, ? ? ? ? ? ? ? ? R = S*Da
kCGBlendModeSourceOut,? ? ? ? ? ? ? ? R = S*(1 - Da)
kCGBlendModeSourceAtop, ? ? ? ? ? ? ? R = S*Da + D*(1 - Sa)
kCGBlendModeDestinationOver,? ? ? ? ? R = S*(1 - Da) + D
kCGBlendModeDestinationIn,? ? ? ? ? ? R = D*Sa
kCGBlendModeDestinationOut, ? ? ? ? ? R = D*(1 - Sa)
kCGBlendModeDestinationAtop,? ? ? ? ? R = S*(1 - Da) + D*Sa
kCGBlendModeXOR,? ? ? ? ? ? ? ? ? ? ? R = S*(1 - Da) + D*(1 - Sa)
kCGBlendModePlusDarker, ? ? ? ? ? ? ? R = MAX(0, (1 - D) + (1 - S))
kCGBlendModePlusLighter ? ? ? ? ? ? ? R = MIN(1, S + D)? };
*/
//self.IM_View.image = UIGraphicsGetImageFromCurrentImageContext();
CGContextRelease(ContextRef);//移除保存的上下文
UIGraphicsEndImageContext();//結(jié)束圖像上下文
/*********************************************************************************/
//圖片的填充,或者拉伸
//self.IM_View.image = [ReadImage stretchableImageWithLeftCapWidth:50 topCapHeight:50];
/*
*? - (UIImage *)stretchableImageWithLeftCapWidth:(NSInteger)leftCapWidth topCapHeight:(NSInteger)topCapHeight? |? - (UIImage *)resizableImageWithCapInsets:(UIEdgeInsets)capInsets
*這個函數(shù)是UIImage的一個實例函數(shù),它的功能是創(chuàng)建一個內(nèi)容可拉伸,而邊角不拉伸的圖片,需要兩個參數(shù),第一個是不拉伸區(qū)域和左邊框的寬度,第二個參數(shù)是不拉伸區(qū)域和上邊框的寬度。
*/
//? ? self.IM_View.image = [ReadImage resizableImageWithCapInsets:UIEdgeInsetsMake(20, 20, 202, 20)];
self.IM_View.image= [ReadImageimageFlippedForRightToLeftLayoutDirection];
/*********************************************************************************/
//計算圖片的大小
longperMBBytes =1024*1024;
CGImageRefcgimage = [UIImageimageNamed:@"zsj.jpg"].CGImage;
size_tbpp =CGImageGetBitsPerPixel(cgimage);
size_tbpc =CGImageGetBitsPerComponent(cgimage);
size_tbytes_per_pixel = bpp / bpc;
longlPixelsPerMB? = perMBBytes/bytes_per_pixel;
longtotalPixel =CGImageGetWidth([UIImageimageNamed:@"zsj.jpg"].CGImage)*CGImageGetHeight([UIImageimageNamed:@"zsj.jpg"].CGImage);
longtotalFileMB = totalPixel * bpp /lPixelsPerMB;
NSLog(@"%ld",totalFileMB);
/*********************************************************************************/
[self.viewaddSubview:self.IM_View];
}
- (void)didReceiveMemoryWarning {
[superdidReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}
*/
@end