使用的是iOS

Question

我正在使用iOS開發的核心圖像框架查找該圖像的像素的顏色我用下面的代碼

CGImageRef imgSource = self.ImageView.image.CGImage; 
CFDataRef m_DataRed1 = CGDataProviderCopyData(CGImageGetDataProvider(imgSource)); 
UInt8 *dataOrignal = (UInt8 *)CFDataGetBytePtr(m_DataRed1); 
double lenghtSource = CFDataGetLength(m_DataRed1); 
NSLog(@"lenght : %f",lenghtSource); 
int redPixel; 
int greenPixel; 
int bluePixel; 

for (int index=0 ; index<lenghtSource; index+=4) { 
    if (dataOrignal[index+1] ==236 || dataOrignal[index+2]==236 || dataOrignal[index+3]==236) { 
     dataOrignal[index + 1] = 205; 
     dataOrignal[index +2] = 25; 
     dataOrignal[index+3]= 55; 
     NSLog(@"this the value of red channel %d", index); 
    } 


} 


NSUInteger width = CGImageGetWidth(imgSource); //202 
NSUInteger height = CGImageGetHeight(imgSource);//173 
size_t bitsPerComponent = CGImageGetBitsPerComponent(imgSource); 
size_t bitsPerPixel = CGImageGetBitsPerPixel(imgSource); 
size_t bytesPerRow = CGImageGetBytesPerRow(imgSource); 


NSLog(@"the width = %u and height=%u of the image is ",width,height); 
NSLog(@"the bits per component is %zd", bitsPerComponent); 
NSLog(@"the bits per pixel is %zd", bitsPerPixel); 
NSLog(@"the bytes per row is %zd" , bytesPerRow); 


CGColorSpaceRef colorspace = CGImageGetColorSpace(imgSource); 
CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imgSource); 
CFDataRef newData = CFDataCreate(NULL, dataOrignal, lenghtSource); 
CGDataProviderRef provider = CGDataProviderCreateWithCFData(newData); 

CGContextRef context = CGBitmapContextCreate(newData, width, height, bitsPerComponent, bytesPerRow, colorspace, bitmapInfo); 
CGPoint point = CGContextGetTextPosition(context); 
NSInteger xx = point.x; 
point.y; 

NSLog(@"this is the value of x axis %d",xx); 

CGImageRef newImg = CGImageCreate(width, height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorspace, bitmapInfo, provider, NULL, true, kCGRenderingIntentDefault); 





UIImage *newImage1 = [UIImage imageWithCGImage:newImg]; 
self.ImageView.image = newImage1; 

，但現在我想什麼是尋找像素的座標像素的x軸和y軸，所以任何人都可以幫助我嗎？或者任何人已經完成了這個代碼？請注意，我沒有使用opencv，如果你知道opencv然後請完全引導

Answer 1

我希望這是你在找什麼。

我將獲取寬度和高度的函數調用移動到for循環的上面，以便它們可以在for循環中用於x和y座標計算。另外，您可能打印了紅色通道的錯誤值。我在適當的版本調用中添加了CG對象。我不知道你是否需要釋放CF對象。

CGImageRef imgSource = self.ImageView.image.CGImage; 
CFDataRef m_DataRed1 = CGDataProviderCopyData(CGImageGetDataProvider(imgSource)); 
UInt8 *dataOrignal = (UInt8 *)CFDataGetBytePtr(m_DataRed1); 
double lenghtSource = CFDataGetLength(m_DataRed1); 
NSLog(@"lenght : %f",lenghtSource); 
int redPixel; 
int greenPixel; 
int bluePixel; 

int triggeredIndex = 0; 
NSUInteger width = CGImageGetWidth(imgSource); //202 
NSUInteger height = CGImageGetHeight(imgSource);//173 

for (int index=0 ; index<lenghtSource; index+=4) 
{ 
    if (dataOrignal[index+1] ==236 || dataOrignal[index+2]==236 || dataOrignal[index+3]==236) 
    { 
     dataOrignal[index+1] = 205; 
     dataOrignal[index+2] = 25; 
     dataOrignal[index+3] = 55; 

     int xcoord = index/(int)(4*width); //Don't think the casts are necessary, but just in case... 
     int ycoord = index % (int)(4*width); 

     //use xcoord and ycoord here... 

     //NSLog(@"this the value of red channel %d", index); 
     //did you mean this? 
     NSLog(@"this the value of red channel %d", dataOrginal[index]); 
    } 
} 


//moved width and height to before the loop 
size_t bitsPerComponent = CGImageGetBitsPerComponent(imgSource); 
size_t bitsPerPixel = CGImageGetBitsPerPixel(imgSource); 
size_t bytesPerRow = CGImageGetBytesPerRow(imgSource); 


NSLog(@"the width = %u and height=%u of the image is ",width,height); 
NSLog(@"the bits per component is %zd", bitsPerComponent); 
NSLog(@"the bits per pixel is %zd", bitsPerPixel); 
NSLog(@"the bytes per row is %zd" , bytesPerRow); 


CGColorSpaceRef colorspace = CGImageGetColorSpace(imgSource); 
CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imgSource); 
CFDataRef newData = CFDataCreate(NULL, dataOrignal, lenghtSource); 
CGDataProviderRef provider = CGDataProviderCreateWithCFData(newData); 

CGContextRef context = CGBitmapContextCreate(newData, width, height, bitsPerComponent,  bytesPerRow, colorspace, bitmapInfo); 
CGPoint point = CGContextGetTextPosition(context); 
NSInteger xx = point.x; 
point.y; //this is unnecessary and does nothing 

NSLog(@"this is the value of x axis %d",xx); 

CGImageRef newImg = CGImageCreate(width, height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorspace, bitmapInfo, provider, NULL, true, kCGRenderingIntentDefault); 





UIImage *newImage1 = [UIImage imageWithCGImage:newImg]; 
self.ImageView.image = newImage1; 

//always remember to clean up after yourself! 
CGImageRelease(imgSource); 
CGColorSpaceRelease(colorspace); 
CGDataProviderRelease(provider); 
CGContextRelease(context); 
CGImageRelease(newImg); 

請記住，不要忘了釋放你的CG對象！