在UIImage(PNG)和RGB8之间转换

本文介绍了在UIImage(PNG)和RGB8之间转换的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我正在使用 https://github.com/PaulSolt/UIImage-Conversion

但是，它似乎在alpha通道上有问题. 从RGBA像素字节数据重构UIImage的问题

However, it seems to have a problem on the alpha channel. Problem reconstituting UIImage from RGBA pixel byte data

我已经简化了这个问题，所以我将它作为一个更简洁的问题来呈现.

I have simplified the problem so I present it as a tidier question.

我下载了Paul的项目，运行它.它会在屏幕中央显示图像-到目前为止，一切都正确.

I download Paul's project, run it. It displays an image in the centre of the screen -- everything so far is correct.

但是他的演示并未测试Alpha.

But his demo is not testing for Alpha.

所以我尝试合成我的按钮图像...

So I attempt to composite my button image...

...在顶部.

结果是:

这是代码-我刚刚修改了AppDelegate_iPad.m:

here is the code -- I have just modified AppDelegate_iPad.m:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    // Override point for customization after application launch.
    {
        UIImage *image = [UIImage imageNamed:@"Icon4.png"];
        int width = image.size.width;
        int height = image.size.height;

        // Create a bitmap
        unsigned char *bitmap = [ImageHelper convertUIImageToBitmapRGBA8:image];

        // Create a UIImage using the bitmap
        UIImage *imageCopy = [ImageHelper convertBitmapRGBA8ToUIImage:bitmap withWidth:width withHeight:height];

        // Cleanup
        if(bitmap) {
            free(bitmap);
            bitmap = NULL;
        }

        // Display the image copy on the GUI
        UIImageView *imageView = [[UIImageView alloc] initWithImage:imageCopy];
        CGPoint center = CGPointMake([UIScreen mainScreen].bounds.size.width / 2.0,
                                     [UIScreen mainScreen].bounds.size.height / 2.0);
        [imageView setCenter:center];
        [window addSubview:imageView];
        [imageView release];
    }


    if( 1 )
    {
        UIImage *image = [UIImage imageNamed:@"OuterButton_Dull.png"];
        int width = image.size.width;
        int height = image.size.height;

        // Create a bitmap
        unsigned char *bitmap = [ImageHelper convertUIImageToBitmapRGBA8:image];

        // Create a UIImage using the bitmap
        UIImage *imageCopy = [ImageHelper convertBitmapRGBA8ToUIImage:bitmap withWidth:width withHeight:height];

        // Cleanup
        if(bitmap) {
            free(bitmap);
            bitmap = NULL;
        }

        // Display the image copy on the GUI
        UIImageView *imageView = [[UIImageView alloc] initWithImage:imageCopy]; // <-- X
        imageView.backgroundColor = [UIColor clearColor];
        CGPoint center = CGPointMake([UIScreen mainScreen].bounds.size.width / 2.0,
                                     [UIScreen mainScreen].bounds.size.height / 2.0);
        [imageView setCenter:center];
        [window addSubview:imageView];
        [imageView release];

    }


    [window makeKeyAndVisible];

    return YES;
}

如果我切换标记为...的行

If I switch the line marked...

// <-- X

说...

... initWithImage:image]; // instead of imageCopy

...它应显示为:

有人在这方面有裂痕吗?它看起来非常好用，但是我不知道问题出在哪里.

Is anyone up having a crack at this? It looks a really nice library to use, but I can't figure out where the problem is.

在UIImage

在UIImage(PNG)和RGB8之间转换

问题描述

推荐答案