标准Lena测试图像下载「建议收藏」

标准Lena测试图像下载「建议收藏」在做图像处理的时候我们往往会使用

大家好,又见面了,我是你们的朋友全栈君。

    在做图像处理的时候我们往往会使用Lena图像进行测试,但网上提供的测试图标准不一。这是Rice University提供的标准测试图,省去大家四处寻找之苦。另外,仔细阅读这个链接,你还会发现其他有用信息^.^

   原文链接: http://www.ece.rice.edu/~wakin/images/

    

Wet Paint

This test image was taken by our group in Duncan Hall at Rice University. The Matlab file for the 1024×1024 image is here.


Lena/Lenna

There seem to be many versions of the Lena (aka “Lenna”) test image available. This problem was noted by Shapiro in his 1993 zerotree paper, and it remains surprisingly true today. This web page is an attempt to clear up some of the confusion (and hopefully not add to it).

The files on this page are given in lossless compression formats. These can be imported into Matlab or opened using photo-editing software. The imread command in Matlab is often useful for importing files such as tiff or bmp. (You may need to convert the data to type double after loading it). For example:

  • lena512 = imread(‘lena512.bmp’);
    lena512 = double(lena512);

To write an image to a file, use imwrite:

  • imwrite(uint8(lena512),’lena512.bmp’,’bmp’);

512×512 Color (24-bit)

This seems to be a pretty widely accepted standard, which originated from a scan of the published photograph (see The Lenna Story). This version is also provided at the USC-SIPI Image Database.

512×512 Grayscale (8-bit)

There doesn’t seem to be as much agreement on this version of the image. At some point, the original color image needed to be converted to grayscale. As Shapiro noted, options included taking only the green component of the RGB representation, or using a luminance-only version. You could also average the RGB components, etc.

I’m not sure how the following version was generated, but it is provided by the Image Communications Lab at UCLA (they apparently obtained it from RPI).

Each of the following files should contain the same information. If there is truly a standard version of the 512×512 Grayscale Lena, this seems to be it.

Comparing Different Versions

To illustrate the importance of using a standard version, let’s look at a few different ones that are floating around. We’ll compress each of them using a JPEG2000 coder (obtained from The JasPer Project).

You can see the Matlab versions of the images here. If you click on the following links, you can see standard jpg files. (These are just for viewing and comparision purposes – use the matlab files for experiments!)

Image 1 is the standard which is discussed in the above section. Image 2 is another version which I’ve seen, and it looks and behaves very similar to the standard. Image 3 is obtained by taking the green component from the 24-bit original (described above). It appears darker than the others, and it is harder to compress. Image 4 is yet another version that seems to be floating around. Visually it is very different from the others (it has less detail), and it is much easier to compress. Results are shown below.


标准Lena测试图像下载「建议收藏」

版权声明:本文内容由互联网用户自发贡献,该文观点仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 举报,一经查实,本站将立刻删除。

发布者:全栈程序员-用户IM,转载请注明出处:https://javaforall.cn/150967.html原文链接:https://javaforall.cn

【正版授权,激活自己账号】: Jetbrains全家桶Ide使用,1年售后保障,每天仅需1毛

【官方授权 正版激活】: 官方授权 正版激活 支持Jetbrains家族下所有IDE 使用个人JB账号...

(0)
blank

相关推荐

  • 主流自动化运维工具支持的功能(运维自动化工具排行)

    主流的自动化运维工具有3种:Puppet、Saltstack和Ansible,用的最多的还是Ansible。Puppet:官网:www.puppetlabs.com,基于rubby开发,C/S架构,支持多平台,可管理配置文件、用户、cron任务、软件包、系统服务等。分为社区版(免费)和企业版(收费),企业版支持图形化配置。Saltstack:官网:https://saltsta…

  • 移动亲情网有漫游费吗_北京移动和家庭套餐介绍

    移动亲情网有漫游费吗_北京移动和家庭套餐介绍为进一步满足客户国内长途及国内漫游通话需求,中国移动北京公司将于近期推出长漫亲情省业务,现就相关事宜通知如下:  一、推出时间  2009年4月18日0时  二、目标客户  动感地带、神州行家园卡  三、具体内容  月功能费1元,客户可指定除北京外国内任一省、自治区或直辖市为亲情省(不含港澳台),客户在北京向亲情省拨打长途每分钟0.19元;客户漫游至亲情省拨打国内电话(不含港澳台)、接听电话每分钟

  • 关于学术论文投稿中的 Cover Letter「建议收藏」

    关于学术论文投稿中的 Cover Letter「建议收藏」  学术期刊报道原始研究工作的论文,一般分为需要快速发表的通信、快报类(communication,letter等)和报道系统研究工作的全文类(fullpaper,article)两种形式。投这两种文章,coverletter和论文Introduction的写法是不同的。    对于需要以通讯或快报形式快速发表的工作,可以是初步的研究结果(preliminaryresult),强调的是工…

  • MySQL timestampdiff()函数[通俗易懂]

    MySQL timestampdiff()函数[通俗易懂]下面说明了TIMESTAMPDIFF函数的语法。TIMESTAMPDIFF(unit,begin,end);TIMESTAMPDIFF函数返回begin-end的结果,其中begin和end是DATE或DATETIME表达式。TIMESTAMPDIFF函数允许其参数具有混合类型,例如,begin是DATE值,end可以是DATETIME值。如果使用DATE值,则TIMESTAMPDIFF函…

  • Docker 零基础从入门到使用

    Docker 零基础从入门到使用

发表回复

您的电子邮箱地址不会被公开。

关注全栈程序员社区公众号