Iphone iOS灰度/黑色&;白色
我对一些将UIImage更改为灰度的代码有问题。它可以在iPhone/iPod上正常工作,但在iPad上,任何已经绘制的东西都会在绘制过程中被拉伸和扭曲 它有时也只会在iPad上在线崩溃 imageRef=CGBitmapContextCreateImage(ctx) 代码如下:Iphone iOS灰度/黑色&;白色,iphone,ios,ipad,core-graphics,Iphone,Ios,Ipad,Core Graphics,我对一些将UIImage更改为灰度的代码有问题。它可以在iPhone/iPod上正常工作,但在iPad上,任何已经绘制的东西都会在绘制过程中被拉伸和扭曲 它有时也只会在iPad上在线崩溃 imageRef=CGBitmapContextCreateImage(ctx) 代码如下: CGContextRef ctx; CGImageRef imageRef = [self.drawImage.image CGImage]; NSUInteger width = CGImageGetWidth(im
CGContextRef ctx;
CGImageRef imageRef = [self.drawImage.image CGImage];
NSUInteger width = CGImageGetWidth(imageRef);
NSUInteger height = CGImageGetHeight(imageRef);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
unsigned char *rawData = malloc(height * width * 4);
NSUInteger bytesPerPixel = 4;
NSUInteger bytesPerRow = bytesPerPixel * width;
NSUInteger bitsPerComponent = 8;
CGContextRef context = CGBitmapContextCreate(rawData, width, height,
bitsPerComponent, bytesPerRow, colorSpace,
kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
CGContextRelease(context);
int byteIndex = 0;
int grayScale;
for(int ii = 0 ; ii < width * height ; ++ii)
{
grayScale = (rawData[byteIndex] + rawData[byteIndex + 1] + rawData[byteIndex + 2]) / 3;
rawData[byteIndex] = (char)grayScale;
rawData[byteIndex+1] = (char)grayScale;
rawData[byteIndex+2] = (char)grayScale;
//rawData[byteIndex+3] = 255;
byteIndex += 4;
}
ctx = CGBitmapContextCreate(rawData,
CGImageGetWidth( imageRef ),
CGImageGetHeight( imageRef ),
8,
CGImageGetBytesPerRow( imageRef ),
CGImageGetColorSpace( imageRef ),
kCGImageAlphaPremultipliedLast );
imageRef = CGBitmapContextCreateImage (ctx);
UIImage* rawImage = [UIImage imageWithCGImage:imageRef];
CGContextRelease(ctx);
self.drawImage.image = rawImage;
free(rawData);
CGContextRef-ctx;
CGImageRef imageRef=[self.drawImage.image CGImage];
NSU整数宽度=CGImageGetWidth(imageRef);
NSU整数高度=CGImageGetHeight(imageRef);
CGColorSpaceRef colorSpace=CGColorSpaceCreateDeviceRGB();
无符号字符*rawData=malloc(高度*宽度*4);
NSU整数字节/像素=4;
NSUInteger bytesPerRow=bytesPerPixel*宽度;
NSU整数比特分量=8;
CGContextRef context=CGBitmapContextCreate(原始数据、宽度、高度、,
bitsPerComponent、bytesPerRow、颜色空间、,
KCGIMAGEAlphaPremultipledLast | kCGBitmapByteOrder32Big);
CGCOLORSPACTERELEASE(色彩空间);
CGContextDrawImage(上下文,CGRectMake(0,0,宽度,高度),imageRef);
CGContextRelease(上下文);
int byteIndex=0;
int灰度;
对于(int ii=0;ii<宽度*高度;++ii)
{
灰度=(原始数据[byteIndex]+原始数据[byteIndex+1]+原始数据[byteIndex+2])/3;
原始数据[字节索引]=(字符)灰度;
原始数据[byteIndex+1]=(字符)灰度;
原始数据[byteIndex+2]=(字符)灰度;
//原始数据[byteIndex+3]=255;
byteIndex+=4;
}
ctx=CGBitmapContextCreate(原始数据,
CGImageGetWidth(imageRef),
CGImageGetHeight(imageRef),
8.
CGImageGetBytesPerRow(imageRef),
CGImageGetColorSpace(imageRef),
KCGIMAGEAlphaPremultipledLast);
imageRef=CGBitmapContextCreateImage(ctx);
UIImage*rawImage=[UIImage imageWithCGImage:imageRef];
CGContextRelease(ctx);
self.drawImage.image=rawImage;
免费(原始数据);
在别处的帮助下解决了这个问题
删除了正在使用的额外上下文并更改了位图格式
CGContextRef ctx;
CGImageRef imageRef = [self.drawImage.image CGImage];
NSUInteger width = CGImageGetWidth(imageRef);
NSUInteger height = CGImageGetHeight(imageRef);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
unsigned char *rawData = malloc(height * width * 4);
NSUInteger bytesPerPixel = 4;
NSUInteger bytesPerRow = bytesPerPixel * width;
NSUInteger bitsPerComponent = CGImageGetBitsPerComponent(imageRef);
ctx = CGBitmapContextCreate(rawData,
width,
height,
bitsPerComponent,
bytesPerRow,
colorSpace,
kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host);
CGContextDrawImage(ctx, CGRectMake(0, 0, width, height), imageRef);
int byteIndex = 0;
int grayScale;
for(int ii = 0 ; ii < width * height ; ++ii)
{
grayScale = (rawData[byteIndex] + rawData[byteIndex + 1] + rawData[byteIndex + 2]) / 3;
rawData[byteIndex] = (char)grayScale;
rawData[byteIndex+1] = (char)grayScale;
rawData[byteIndex+2] = (char)grayScale;
//rawData[byteIndex+3] = 255;
byteIndex += 4;
}
imageRef = CGBitmapContextCreateImage(ctx);
UIImage* rawImage = [UIImage imageWithCGImage:imageRef];
CGColorSpaceRelease(colorSpace);
CGContextRelease(ctx);
self.drawImage.image = rawImage;
free(rawData);
CGContextRef-ctx;
CGImageRef imageRef=[self.drawImage.image CGImage];
NSU整数宽度=CGImageGetWidth(imageRef);
NSU整数高度=CGImageGetHeight(imageRef);
CGColorSpaceRef colorSpace=CGColorSpaceCreateDeviceRGB();
无符号字符*rawData=malloc(高度*宽度*4);
NSU整数字节/像素=4;
NSUInteger bytesPerRow=bytesPerPixel*宽度;
NSUInteger bitsPerComponent=CGImageGetBitsPerComponent(imageRef);
ctx=CGBitmapContextCreate(原始数据,
宽度,
高度,
比特组件,
拜特斯佩罗,
色彩空间,
KCGIMAGEAlphaPremultipledFirst | KCGBitMapByteOrder32主机);
CGContextDrawImage(ctx、CGRectMake(0、0、宽度、高度)、imageRef);
int byteIndex=0;
int灰度;
对于(int ii=0;ii<宽度*高度;++ii)
{
灰度=(原始数据[byteIndex]+原始数据[byteIndex+1]+原始数据[byteIndex+2])/3;
原始数据[字节索引]=(字符)灰度;
原始数据[byteIndex+1]=(字符)灰度;
原始数据[byteIndex+2]=(字符)灰度;
//原始数据[byteIndex+3]=255;
byteIndex+=4;
}
imageRef=CGBitmapContextCreateImage(ctx);
UIImage*rawImage=[UIImage imageWithCGImage:imageRef];
CGCOLORSPACTERELEASE(色彩空间);
CGContextRelease(ctx);
self.drawImage.image=rawImage;
免费(原始数据);
考虑利用iOS 6中提供的过滤器
void ToMonochrome()
{
var mono = new CIColorMonochrome();
mono.Color = CIColor.FromRgb(1, 1, 1);
mono.Intensity = 1.0f;
var uiImage = new UIImage("Images/photo.jpg");
mono.Image = CIImage.FromCGImage(uiImage.CGImage);
DisplayFilterOutput(mono, ImageView);
}
static void DisplayFilterOutput(CIFilter filter, UIImageView imageView)
{
CIImage output = filter.OutputImage;
if (output == null)
return;
var context = CIContext.FromOptions(null);
var renderedImage = context.CreateCGImage(output, output.Extent);
var finalImage = new UIImage(renderedImage);
imageView.Image = finalImage;
}
如果你在iPad上使用与iPhone相同的图像,会发生什么?我怀疑图像格式或其他方面存在差异。另外,请注意,有一种更好的算法可以转换为灰度,将30%的红色值、59%的绿色值和11%的蓝色值相加,如下所示:灰度=((rawData[byteIndex]*0.3f)+(rawData[byteIndex+1]*0.59)+(rawData[byteIndex+2]*0.11));图像格式每次都是相同的。你可以随心所欲地画画,然后点击灰度按钮。它只是在iPad上倾斜,经常在imageRef=CGBitmapContextCreateImage(ctx)上崩溃;仅在iPad上