.h文件
#import <Cocoa/Cocoa.h>
#import "NSImage+Conversion.h"
void releaseMyContextData(CGContextRef content);
CGContextRef MyCreateBitmapContext (int pixelsWide,
int pixelsHigh);
//判断文件是否存在
BOOL pathIsAFile(NSString *path);
//通过路径加载NSImage
这样写之后 不能象imageName方法那样可以自动识别大图还是小图(在Retina时)
NSImage* loadNSImageWithName(NSString * path);
//通过路径加载CGImageRef
CGImageRef createCGImageWithName(NSString * path);
//NSImage to CGImage
CGImageRef createCGImageRefFromNSImage(NSImage* image);
//把一张简单的黑白图对象转成一张mask图片对象
CGImageRef createMaskWithImage(CGImageRef image);
//这个是苹果官方的标准写法
NSImage* createNSImageFromCGImageRef2(CGImageRef image);
//CGImage to NSImage
NSImage* createNSImageFromCGImageRef(CGImageRef image);
//缩放图片
按宽高 (既新的返回图片的宽变成width
高变成height)
CGImageRef createScaleImageByXY(CGImageRef image,
float width, float height);
//缩放图片
按比例
CGImageRef createScaleImageByRatio(NSImage *image,
float fratio);
BOOL saveImagepng(CGImageRef imageRef,
NSString *strpath);
BOOL saveImagejpg(CGImageRef imageRef,
NSString *strpath);
.m文件
#import "Utilities.h"
void releaseMyContextData(CGContextRef content){
void *imgdata =CGBitmapContextGetData(content);
CGContextRelease(content);
if (imgdata) {
free(imgdata);
}
}
CGContextRef MyCreateBitmapContext (int pixelsWide,
int pixelsHigh)
{
CGContextRef context =
NULL;
CGColorSpaceRef colorSpace;
GLubyte
*bitmapData;
int
bitmapByteCount;
int
bitmapBytesPerRow;
bitmapBytesPerRow = (pixelsWide *
4);
bitmapByteCount = (bitmapBytesPerRow * pixelsHigh);
colorSpace =
CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);//CGColorSpaceCreateDeviceRGB();//
//z这里初始化用malloc和calloc都可以 (注意:malloc只能分配内存
初始化所分配的内存空间 calloc则可以)
//在此需要特别注意的是
第二个参数传0进去
如果传比较大的数值进去的话 则会内存泄漏
比如传8之类的就会出现大的泄漏问题
/*如果调用成功,函数malloc()和函数calloc()都
将返回所分配的内存空间的首地址。
函数malloc()和函数calloc()的主要区别是前
者不能初始化所分配的内存空间,而后者能。如
果由malloc()函数分配的内存空间原来没有被
使用过，则其中的每一位可能都是0;反之,如果
这部分内存曾经被分配过,则其中可能遗留有各
种各样的数据。也就是说，使用malloc()函数
的程序开始时(内存空间还没有被重新分配)能
正常进行,但经过一段时间(内存空间还已经被
重新分配)可能会出现问题
函数calloc()会将所分配的内存空间中的每一
位都初始化为零,也就是说,如果你是为字符类
型或整数类型的元素分配内存,那麽这些元素将
保证会被初始化为0;如果你是为指针类型的元
素分配内存,那麽这些元素通常会被初始化为空
指针;如果你为实型数据分配内存,则这些元素
会被初始化为浮点型的零*/
//NSLog(@"%lu", sizeof(GLubyte));
bitmapData = (GLubyte*)calloc(bitmapByteCount,sizeof(GLubyte));//or
malloc(bitmapByteCount);//
if (bitmapData ==
NULL) {
fprintf(stderr,
"Memory not allocated!");
return
NULL;
}
context =
CGBitmapContextCreate(bitmapData,
pixelsWide,
pixelsHigh,
8,
bitmapBytesPerRow,
colorSpace,
kCGImageAlphaPremultipliedLast);
if (context ==
NULL) {
free(bitmapData);
fprintf(stderr,
"Context not created!");
return
NULL;
}
CGColorSpaceRelease(colorSpace);
return context;
}
//---------------------------------------------------------------------------------
// createCGImageWithName:
//
// simple utility function that create an image from a name by looking into the main bundle
//---------------------------------------------------------------------------------
CGImageRef createCGImageWithName(NSString * path)
{
CGImageRef image =
NULL;
CFURLRef url = (CFURLRef) [NSURL
fileURLWithPath: path];
CGImageSourceRef src =
CGImageSourceCreateWithURL(url, NULL);
if( src ) {
//NSDictionary* options = [NSDictionary dictionaryWithObjectsAndKeys: (id)kCFBooleanFalse, (id)kCGImageSourceShouldCache, (id)kCFBooleanTrue, (id)kCGImageSourceShouldAllowFloat, nil];//[NSNumber numberWithBool:YES],
(NSString *)kCGImageSourceCreateThumbnailFromImageIfAbsent, [NSNumber numberWithInt:360], (NSString *)kCGImageSourceThumbnailMaxPixelSize, nil];
image = CGImageSourceCreateImageAtIndex(src,
0, NULL);//(CFDictionaryRef)options);
CFRelease(src);
if(!image)
NSLog(@"Warning: CGImageSourceCreateImageAtIndex failed on file %@ (ptr size=%lu)",path,sizeof(void*));
}
return image;
}
BOOL pathIsAFile(NSString *path){
NSFileManager *fileManager = [NSFileManager
defaultManager];
BOOL isDir, valid = [fileManager
fileExistsAtPath:path isDirectory:&isDir];
if (valid) {
}else{
return NO;
}
return
YES;
}
NSImage* loadNSImageWithName(NSString * path){
NSFileManager *fileManager = [NSFileManager
defaultManager];
BOOL isDir, valid = [fileManager
fileExistsAtPath:path isDirectory:&isDir];
if (valid) {
}else{
return nil;
}
if ([path isEqualToString:@""] || !path) {
return nil;
}
CGImageRef img =
createCGImageWithName(path);
if (!img) {
return nil;
}
NSImage *image = [[NSImage
alloc] initWithCGImage:img];
CFRelease(img);
return [image autorelease];
//return [NSImage imageNamed:path];
}
BOOL saveImagepng(CGImageRef imageRef,
NSString *strpath)
{
NSString *finalPath = [NSString
stringWithString:strpath];
CFURLRef url =
CFURLCreateWithFileSystemPath (
kCFAllocatorDefault,
(CFStringRef)finalPath,
kCFURLPOSIXPathStyle,
false);
CGImageDestinationRef dest =
CGImageDestinationCreateWithURL(url, CFSTR("public.png"),
1, NULL);
assert(dest);
CGImageDestinationAddImage(dest, imageRef,
NULL);
assert(dest);
if (dest == NULL) {
NSLog(@"CGImageDestinationCreateWithURL failed");
}
//NSLog(@"%@", dest);
assert(CGImageDestinationFinalize(dest));
//这三句话用来释放对象
CFRelease(dest);
//CGImageRelease(imageRef);
CFRelease(url);
return
YES;
}
BOOL saveImagejpg(CGImageRef imageRef,
NSString *strpath)
{
NSString *finalPath = [NSString
stringWithString:strpath];
CFURLRef url =
CFURLCreateWithFileSystemPath (
kCFAllocatorDefault,
(CFStringRef)finalPath,
kCFURLPOSIXPathStyle,
false);
CGImageDestinationRef dest =
NULL;
dest = CGImageDestinationCreateWithURL(url,
CFSTR("public.jpeg"),
1, NULL);
assert(dest);
CFMutableDictionaryRef mSaveMetaAndOpts =
CFDictionaryCreateMutable(nil,
0,
&kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
CFDictionarySetValue(mSaveMetaAndOpts,
kCGImageDestinationLossyCompressionQuality,
[NSNumber
numberWithFloat:0.8]);
CGImageDestinationAddImage(dest, imageRef, (CFDictionaryRef)mSaveMetaAndOpts);
CFRelease(mSaveMetaAndOpts);
//CGImageDestinationAddImage(dest, imageRef, NULL);
assert(dest);
if (dest == NULL) {
NSLog(@"CGImageDestinationCreateWithURL failed");
}
//NSLog(@"%@", dest);
assert(CGImageDestinationFinalize(dest));
//这三句话用来释放对象
CFRelease(dest);
//CGImageRelease(imageRef);
//CFRetain(url);
CFRelease(url);
return
YES;
}
CGImageRef createCGImageRefFromNSImage(NSImage* image)
{
NSData *imageData;
CGImageRef imageRef;
@try {
imageData = [image
TIFFRepresentation];
if (imageData) {
CGImageSourceRef imageSource =
CGImageSourceCreateWithData((CFDataRef)imageData,
NULL);
NSDictionary* options = [NSDictionary
dictionaryWithObjectsAndKeys:
(id)kCFBooleanFalse, (id)kCGImageSourceShouldCache,
(id)kCFBooleanTrue, (id)kCGImageSourceShouldAllowFloat,
nil];
//要用这个带option的 kCGImageSourceShouldCache指出不需要系统做cache操作
默认是会做的
imageRef =
CGImageSourceCreateImageAtIndex(imageSource,
0, (CFDictionaryRef)options);
CFRelease(imageSource);
return imageRef;
}else{
return NULL;
}
}
@catch (NSException *exception) {
}
@finally {
}
return
NULL;
}
//这个是苹果官方的标准写法
NSImage* createNSImageFromCGImageRef2(CGImageRef image)
{
NSImage* newImage =
nil;
#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5
NSBitmapImageRep*
newRep = [[NSBitmapImageRep alloc]
initWithCGImage:image];
NSSize imageSize;
// Get the image dimensions.
imageSize.height =
CGImageGetHeight(image);
imageSize.width =
CGImageGetWidth(image);
newImage = [[NSImage
alloc] initWithSize:imageSize];
[newImage
addRepresentation:newRep];
[newRep
release];
#else
NSRect imageRect = NSMakeRect(0.0,
0.0, 0.0,
0.0);
CGContextRef imageContext =
nil;
// Get the image dimensions.
imageRect.size.height = CGImageGetHeight(image);
imageRect.size.width = CGImageGetWidth(image);
// Create a new image to receive the Quartz image data.
newImage = [[NSImage alloc] initWithSize:imageRect.size];
[newImage lockFocus];
// Get the Quartz context and draw.
imageContext = (CGContextRef)[[NSGraphicsContext currentContext] graphicsPort];
CGContextDrawImage(imageContext, *(CGRect*)&imageRect, image);
[newImage unlockFocus];
#endif
return newImage;//[newImage autorelease];
}
NSImage* createNSImageFromCGImageRef(CGImageRef image){
NSRect imageRect =
NSMakeRect(0,
0, 0, 0);
CGContextRef imageContext =
nil;
NSImage *newImage =
nil;
//Get the image dimensions
@try {
imageRect.size.height =
CGImageGetHeight(image);
imageRect.size.width =
CGImageGetWidth(image);
//要转换成整数，否则在大图片时可能出现异常
//Create a new image to receive the Quartz image data
newImage = [[NSImage
alloc] initWithSize:imageRect.size];
[newImage
lockFocus];
//Get the Quartz context and draw
imageContext = (CGContextRef)[[NSGraphicsContext
currentContext] graphicsPort];
//CGContextSaveGState(imageContext);
CGContextDrawImage(imageContext, *(CGRect*)&imageRect, image);
//CGContextRestoreGState(imageContext);
[newImage
unlockFocus];
//CFRelease(imageContext);
}
@catch (NSException *exception) {
}
@finally {
}
return newImage;
}
CGImageRef createMaskWithImage(CGImageRef image)
{
//NSAssert(image != NULL, @"The Foo pointer must not be NULL!");
if (image == NULL) {
return NULL;
}
@try {
int mw = (int)CGImageGetWidth(image);