bitmap

How to convert an image into point data for ggplot2 scatterplot

由 僤鯓⒐⒋嵵緔 提交于 2020-05-12 15:55:07
问题 I recently found a package on Github where the dev analyzed fan-curated data on the 248 installments of the Spy vs Spy comic by Antonio Prohias appearing in Mad Magazine. He goes through some basic exploratory data analysis, computes a running net score of Black Spy victories and then runs a non-parametric test (Wald Wolfowitz test) to look at clusters of consecutive victories by one of the Spies in order to ascertain if Prohias kept the score balance by reversing the previous outcome, or if

WinAPI/GDI: why snapshot of large windows includes taskbar?

由 心已入冬 提交于 2020-04-30 08:54:47
问题 I am using GDI+ to take window snapshot, the code is: CComBSTR bstrfname (fname); HDC hdc = CreateCompatibleDC (hDC); HBITMAP hbmp = CreateCompatibleBitmap (hDC, CFG_WIDTH, CFG_HEIGHT); HBITMAP hbmp0 = (HBITMAP)SelectObject (hdc, hbmp); BitBlt (hdc, 0, 0, CFG_WIDTH, CFG_HEIGHT, hDC, 0, 0, SRCCOPY); Gdiplus::Bitmap *bmp = new Gdiplus::Bitmap (hbmp, NULL); CLSID encoderClsid; GetEncoderClsid (L"image/png", &encoderClsid); bmp->Save (bstrfname, &encoderClsid, NULL); delete bmp; SelectObject (hdc

WinAPI/GDI: why snapshot of large windows includes taskbar?

由 老子叫甜甜 提交于 2020-04-30 08:53:00
问题 I am using GDI+ to take window snapshot, the code is: CComBSTR bstrfname (fname); HDC hdc = CreateCompatibleDC (hDC); HBITMAP hbmp = CreateCompatibleBitmap (hDC, CFG_WIDTH, CFG_HEIGHT); HBITMAP hbmp0 = (HBITMAP)SelectObject (hdc, hbmp); BitBlt (hdc, 0, 0, CFG_WIDTH, CFG_HEIGHT, hDC, 0, 0, SRCCOPY); Gdiplus::Bitmap *bmp = new Gdiplus::Bitmap (hbmp, NULL); CLSID encoderClsid; GetEncoderClsid (L"image/png", &encoderClsid); bmp->Save (bstrfname, &encoderClsid, NULL); delete bmp; SelectObject (hdc

Disable Image blending on a PictureBox

由 百般思念 提交于 2020-04-29 09:52:39
问题 In my Windows Forms program, I have a PictureBox . The bitmap image inside it is small, 5 x 5 pixels. When assigned to a PictureBox , it becomes very blurry. I tried finding something like blending mode, blurring mode, or anti-aliasing mode, but I had no luck. This is what I want This is not what I want 回答1: The problem : A Bitmap, with a size that is much smaller than the container used to show it, is blurred and the otherwise sharp edges of the well-defined areas of color are

Disable Image blending on a PictureBox

由 回眸只為那壹抹淺笑 提交于 2020-04-29 09:51:32
问题 In my Windows Forms program, I have a PictureBox . The bitmap image inside it is small, 5 x 5 pixels. When assigned to a PictureBox , it becomes very blurry. I tried finding something like blending mode, blurring mode, or anti-aliasing mode, but I had no luck. This is what I want This is not what I want 回答1: The problem : A Bitmap, with a size that is much smaller than the container used to show it, is blurred and the otherwise sharp edges of the well-defined areas of color are

Disable Image blending on a PictureBox

由 笑着哭i 提交于 2020-04-29 09:50:10
问题 In my Windows Forms program, I have a PictureBox . The bitmap image inside it is small, 5 x 5 pixels. When assigned to a PictureBox , it becomes very blurry. I tried finding something like blending mode, blurring mode, or anti-aliasing mode, but I had no luck. This is what I want This is not what I want 回答1: The problem : A Bitmap, with a size that is much smaller than the container used to show it, is blurred and the otherwise sharp edges of the well-defined areas of color are

使用libjpeg进行图片压缩

由 空扰寡人 提交于 2020-04-07 21:26:25
简介 由于工作原因，boss下达的任务就大概说了对图片进行压缩寻找比较合理的方式，还举了一个项目中的坑，就是系统原生的Bitmap.compress设置质量参数为100生成图片会变大的坑。所以我打算用一点时间研究研究Bitmap在内存和外存中的情况。首先需要对图片进行压缩，大家都知道图片是Android里面一个大坑，具体的问题有: OOM，一不留神就用OOM来冲冲喜，所以网上就有了很多解决oom问题的建议，但是由于网友的水平不一也导致建议参差不齐。（内存） 图片压缩再加载失真严重，或者压缩率不够达不到项目要求的效果。（外存） 那我今天就要解决的就是通过今天查阅的资料和自己的判断，还有实践归档一下图片在Android上的问题。并且给出自己解决图片压缩问题的解决方案和实际操作。 1、为什么Android上的图片就不如IOS上的？ libjpeg是广泛使用的开源JPEG图像库，安卓也依赖libjpeg来压缩图片。但是安卓并不是直接封装的libjpeg，而是基于了另一个叫Skia的开源项目来作为的图像处理引擎。Skia是谷歌自己维护着的一个大而全的引擎，各种图像处理功能均在其中予以实现，并且广泛的应用于谷歌自己和其它公司的产品中（如：Chrome、Firefox、 Android等）。Skia对libjpeg进行了良好的封装，基于这个引擎可以很方便为操作系统、浏览器等开发图像处理功能。

Android网络通信：Volley（二）

由 余生长醉 提交于 2020-04-07 18:29:53
1、ImageRequest的用法 前面我们已经学习过了StringRequest和JsonRequest的用法，并且总结出了它们的用法都是非常类似的，基本就是进行以下三步操作即可： 1. 创建一个RequestQueue对象。 2. 创建一个Request对象。 3. 将Request对象添加到RequestQueue里面。 其中，StringRequest和JsonRequest都是继承自Request的，所以它们的用法才会如此类似。那么不用多说，今天我们要学习的ImageRequest，相信你从名字上就已经猜出来了，它也是继承自Request的，因此它的用法也是基本相同的，首先需要获取到一个RequestQueue对象，可以调用如下方法获取到： RequestQueue mQueue = Volley.newRequestQueue(context); 接下来自然要去new出一个ImageRequest对象了，代码如下所示： ImageRequest imageRequest = new ImageRequest( "http://developer.android.com/images/home/aw_dac.png", new Response.Listener<Bitmap>() { @Override public void onResponse(Bitmap

[转]Android图片异步加载

由 落爺英雄遲暮 提交于 2020-04-07 13:18:24
获取图片工具类： public class ApacheUtility { /** * 获取图片流 * * @param uri 图片地址 * @return * @throws MalformedURLException */ public static InputStream GetImageByUrl(String uri) throws MalformedURLException { URL url = new URL(uri); URLConnection conn; InputStream is; try { conn = url.openConnection(); conn.connect(); is = conn.getInputStream(); // 或者用如下方法 // is=(InputStream)url.getContent(); return is; } catch (IOException e) { e.printStackTrace(); } return null; } /** * 获取Bitmap * * @param uri 图片地址 * @return */ public static Bitmap GetBitmapByUrl(String uri) { Bitmap bitmap; InputStream is; try { is =

Android网络图片缓存

由 旧巷老猫 提交于 2020-04-07 13:18:06
获取一张图片，从三个地方进行获取，首先是内存缓存，然后是文件缓存，最后才从网络中获取。 //内存缓存 public class ImageMemoryCache { /** * 从内存读取数据速度是最快的，为了更大限度使用内存，这里使用了两层缓存。 硬引用缓存不会轻易被回收，用来保存常用数据，不常用的转入软引用缓存。 */ private static final int SOFT_CACHE_SIZE = 15; // 软引用缓存容量 private static LruCache<String, Bitmap> mLruCache ; // 硬引用缓存 private static LinkedHashMap<String, SoftReference<Bitmap>> mSoftCache ; // 软引用缓存 public ImageMemoryCache(Context context) { int memClass = ((ActivityManager) context .getSystemService(Context. ACTIVITY_SERVICE )).getMemoryClass(); int cacheSize = 1024 * 1024 * memClass / 4; // 硬引用缓存容量，为系统可用内存的1/4 mLruCache = new
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