#import
@interfaceImageHelper : NSObject {
}
/** Convertsa UIImage to RGBA8 bitmap.
@param image - a UIImage to be converted
@return a RGBA8 bitmap, or NULL if any memoryallocation issues. Cleanup memory with free() when done.
*/
+ (unsignedchar*) convertUIImageToBitmapRGBA8:(UIImage *)image;
/** A helperroutine used to convert a RGBA8 to UIImage
@return a new context that is owned by thecaller
*/
+(CGContextRef) newBitmapRGBA8ContextFromImage:(CGImageRef)image;
/** Convertsa RGBA8 bitmap to a UIImage.
@param buffer - the RGBA8 unsigned char *bitmap
@param width - the number of pixels wide
@param height - the number of pixels tall
@return a UIImage that is autoreleased or nilif memory allocation issues
*/
+ (UIImage *)convertBitmapRGBA8ToUIImage:(unsignedchar*)buffer
withWidth:(int)width
withHeight:(int)height;
@end
#import"ImageHelper.h"
@implementationImageHelper
+ (unsignedchar*) convertUIImageToBitmapRGBA8:(UIImage *) image {
CGImageRef imageRef=image.CGImage;
// Create a bitmap context to draw the uiimage into
CGContextRef context =[self newBitmapRGBA8ContextFromImage:imageRef];
if(!context) {
returnNULL;
}
size_t width=CGImageGetWidth(imageRef);
size_t height=CGImageGetHeight(imageRef);
CGRect rect=CGRectMake(0,0, width, height);
// Draw image into the context to get the raw image data
CGContextDrawImage(context, rect,imageRef);
// Get a pointer to the data
unsignedchar*bitmapData = (unsignedchar*)CGBitmapContextGetData(context);
// Copy the data and release the memory (return memory
allocated with new)
size_t bytesPerRow =CGBitmapContextGetBytesPerRow(context);
size_t bufferLength= bytesPerRow *height;
unsignedchar*newBitmap =NULL;
if(bitmapData) {
newBitmap=(unsignedchar*)malloc(sizeof(unsignedchar) *bytesPerRow *height);
if(newBitmap){// Copy
the data
for(inti =0; i
newBitmap[i]=bitmapData[i];
}
}
free(bitmapData);
}else{
NSLog(@"Error getting bitmap pixel data\n");
}
CGContextRelease(context);
returnnewBitmap;
}
+(CGContextRef) newBitmapRGBA8ContextFromImage:(CGImageRef) image {
CGContextRef context=NULL;
CGColorSpaceRef colorSpace;
uint32_t*bitmapData;
size_t bitsPerPixel=32;
size_t bitsPerComponent=8;
size_t bytesPerPixel= bitsPerPixel /bitsPerComponent;
size_t width=CGImageGetWidth(image);
size_t height=CGImageGetHeight(image);
size_t bytesPerRow= width*bytesPerPixel;
size_t bufferLength= bytesPerRow *height;
colorSpace=CGColorSpaceCreateDeviceRGB();
if(!colorSpace) {
NSLog(@"Error allocating color space RGB\n");
returnNULL;
}
// Allocate memory for image data
bitmapData = (uint32_t *)malloc(bufferLength);
if(!bitmapData) {
NSLog(@"Error allocating memory for bitmap\n");
CGColorSpaceRelease(colorSpace);
returnNULL;
}
//Create bitmap context
context=CGBitmapContextCreate(bitmapData,
width,
height,
bitsPerComponent,
bytesPerRow,
colorSpace,
kCGImageAlphaPremultipliedLast);// RGBA
if(!context) {
free(bitmapData);
NSLog(@"Bitmap context not created");
}
CGColorSpaceRelease(colorSpace);
returncontext;
}
+ (UIImage *)convertBitmapRGBA8ToUIImage:(unsignedchar*) buffer
withWidth:(int) width
withHeight:(int) height {
size_t bufferLength= width* height *4;
CGDataProviderRef provider=CGDataProviderCreateWithData(NULL, buffer,bufferLength, NULL);
size_t bitsPerComponent=8;
size_t bitsPerPixel=32;
size_t bytesPerRow=4*width;
CGColorSpaceRef colorSpaceRef=CGColorSpaceCreateDeviceRGB();
if(colorSpaceRef ==NULL) {
NSLog(@"Error allocating color space");
CGDataProviderRelease(provider);
returnnil;
}
CGBitmapInfo bitmapInfo= kCGBitmapByteOrderDefault |kCGImageAlphaPremultipliedLast;
CGColorRenderingIntent renderingIntent=kCGRenderingIntentDefault;
CGImageRef iref=CGImageCreate(width,
height,
bitsPerComponent,
bitsPerPixel,
bytesPerRow,
colorSpaceRef,
bitmapInfo,
provider,// data provider
NULL,// decode
YES,// should
interpolate
renderingIntent);
uint32_t* pixels= (uint32_t*)malloc(bufferLength);
if(pixels ==NULL) {
NSLog(@"Error: Memory not allocated for bitmap");
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpaceRef);
CGImageRelease(iref);
returnnil;
}
CGContextRef context=CGBitmapContextCreate(pixels,
width,
height,
bitsPerComponent,
bytesPerRow,
colorSpaceRef,
bitmapInfo);
if(context ==NULL) {
NSLog(@"Error context not created");
free(pixels);
}
UIImage*image =nil;
if(context) {
CGContextDrawImage(context, CGRectMake(0.0f,0.0f, width, height), iref);
CGImageRef imageRef=CGBitmapContextCreateImage(context);
// Support both iPad 3.2 and iPhone 4 Retina displays
with the correct scale
if([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)]){
floatscale =[[UIScreen mainScreen]scale];
image=[UIImage imageWithCGImage:imageRef scale:scaleorientation:UIImageOrientationUp];
}else{
image=[UIImage imageWithCGImage:imageRef];
}
CGImageRelease(imageRef);
CGContextRelease(context);
}
CGColorSpaceRelease(colorSpaceRef);
CGImageRelease(iref);
CGDataProviderRelease(provider);
if(pixels) {
free(pixels);
}
returnimage;
}
@end
