issue in generating image files in mac os x app cocoa - objective-c

Question

-(void)processImage:(NSString*)inputPath:(int)imageWidth:(int)imageHeight:(NSString*)outputPath {
// NSImage * img = [NSImage imageNamed:inputPath];
NSImage *image = [[NSImage alloc] initWithContentsOfFile:inputPath];
[image setSize: NSMakeSize(imageWidth,imageHeight)];
[[image TIFFRepresentation] writeToFile:outputPath atomically:NO];
NSLog(#"image file created");
}
- (IBAction)processImage:(id)sender {
NSTimeInterval timeStamp = [[NSDate date] timeIntervalSince1970];
// NSTimeInterval is defined as double
NSNumber *timeStampObj = [NSNumber numberWithInt:timeStamp];
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterNoStyle];
NSString *convertNumber = [formatter stringForObjectValue:timeStampObj];
NSLog(#"timeStampObj:: %#", convertNumber);
fileNameNumber = [[convertNumber stringByAppendingString:[self genRandStringLength:8]] retain];
int i; // Loop counter.
// Loop through all the files and process them.
for( i = 0; i < [files count]; i++ )
{
inputFilePath = [[files objectAtIndex:i] retain];
NSLog(#"filename::: %#", inputFilePath);
// Do something with the filename.
[selectedFile setStringValue:inputFilePath];
NSLog(#"selectedFile:::: %#", selectedFile);
}
NSLog(#"curdir:::::%#", inputFilePath);
NSString *aString = [[NSString stringWithFormat:#"%#%#%#", thumbnailDirPath , #"/" , fileNameNumber] retain];
fileNameJPG = [[aString stringByAppendingString:#"_small.jpg"] retain];
fileNameJPG1 = [[aString stringByAppendingString:#".jpg"] retain];
fileNameJPG2 = [[aString stringByAppendingString:#"_H.jpg"] retain];
[self processImage:inputFilePath: 66 :55 :fileNameJPG];
[self processImage:inputFilePath: 800 :600 :fileNameJPG1];
[self processImage:inputFilePath: 320 :240 :fileNameJPG2];
}
The issue I am facing is that the above code is generating 3 files with different names(as I have defined the name should be) having the same size of all 3 files but not with the dimensions or width/length I pass to the function.
What can be the issue ?

Answer 1

NSImage objects are immutable. So image is not modified when you change its size.
You should use something like the following code (adapted from here).
-(void)saveImageAtPath:(NSString*)sourcePath toPath:(NSString*)targetPath withWidth:(int)targetWidth andHeight:(int)targetHeight
{
NSImage *sourceImage = [[NSImage alloc] initWithContentsOfFile:sourcePath];
NSImage *targetImage = [[NSImage alloc] initWithSize: NSMakeSize(targetWidth, targetHeight)];
NSSize sourceSize = [sourceImage size];
NSRect sourceRect = NSMakeRect(0, 0, sourceSize.width, sourceSize.height);
NSRect targetRect = NSMakeRect(0, 0, targetWidth, targetWidth);
[targetImage lockFocus];
[sourceImage drawInRect:targetRect fromRect:sourceRect operation: NSCompositeSourceOver fraction: 1.0];
[targetImage unlockFocus];
[[targetImage TIFFRepresentation] writeToFile:targetPath atomically:NO];
NSLog(#"image file created");
[sourceImage release];
[targetImage release];
}