Question

今天我的任务是将字节数组转换为图像

首先我尝试将图像转换为字节数组： -

首先要将Image转换为Byte数组，我们要做的是将特定图像[UIImage]转换为NSData。然后我们将NSData转换为Byte数组。在这里，我将给出示例代码，只需通过...

//Converting UIImage to NSData
    UIImage *image = [UIImage imageNamed: @"photo-04.jpg"];

    NSData *imageData = UIImagePNGRepresentation(image);

    //Converting NSData to Byte array
    NSUInteger len = [imageData length];
    NSLog(@"Byte Lendata1  %lu",(unsigned long)len);

    Byte *byteData = (Byte*)malloc(len);
    memcpy(byteData, [imageData bytes], len);

我尝试将此字节转换为imageView

 const unsigned char *bytes = [imageData bytes];

    NSUInteger length = [imageData length];

    NSMutableArray *byteArray = [NSMutableArray array];

    for (NSUInteger i = 0; i < length; i++) {
        [byteArray addObject:[NSNumber numberWithUnsignedChar:bytes[i]]];
    }
    NSDictionary *dictJson = [NSDictionary dictionaryWithObjectsAndKeys:
                              byteArray, @"photo",
                              nil];
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dictJson options:0 error:NULL];
    NSLog(@"");
    UIImage *image1 = [UIImage imageWithData:jsonData];

    UIImageView *imgView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 100, 50)];


    imgView.image=image1;

我有输出转换图像到字节数组但我想将字节数组转换为图像所以请先帮助我谢谢。

Answer 1

首先，您需要将字节转换为NSData

NSData *imageData = [NSData dataWithBytes:bytesData length:length];

然后，将数据转换回图像。

UIImage *image = [UIImage imageWithData:imageData];

我建议您在发生问题时首先搜索文档。

以下是全部：

UIImage *image = [UIImage imageNamed:@"RAC.png"];

NSData *imageData = UIImagePNGRepresentation(image);
// UIImageJPGRepresentation also work

NSInteger length = [imageData length];

Byte *byteData = (Byte*)malloc(length);
memcpy(byteData, [imageData bytes], length);

NSData *newData = [NSData dataWithBytes:byteData length:length];

UIImage *newImage = [UIImage imageWithData:newData];

UIImageView *imageView = [[UIImageView alloc] initWithImage:newImage];
imageView.frame = CGRectMake(50, 50, 100, 100);
[self.view addSubview:imageView];

Answer 2

您使用错误的格式

表示数据

您的图片格式为jpg，并且您使用的是PNG数据。

对于jpg或jpeg格式，您应使用UIImageJPEGRepresentation

NSData * UIImageJPEGRepresentation (
   UIImage *image,
   CGFloat compressionQuality
);

所需的陈述将是

NSData *imageData = UIImageJPEGRepresentation(image, 0.0f);// Set Compression quality to 0.0. You can change it.

对于png格式，您应该使用UIImagePNGRepresentation

NSData * UIImagePNGRepresentation (
   UIImage *image
);

所需的陈述将是

NSData *imageData = UIImagePNGRepresentation(image);

要将NSData转换回UIImage，请使用

UIImage *image = [UIImage imageWithData:imageData];

阅读APPLE DOCS。看图像操作

如何在ios中将字节数组转换为图像

2 个答案: