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Large app size due to images. How to compress .PNG images?

由 ♀尐吖头ヾ 提交于 2019-12-23 07:32:30
问题 I am developing an app which has a lot of images to work on due to which the size of my app has become very large. I want to compress or something like that to reduce the size of app. Any idea? 回答1: .png -files which are placed in the res/drawable are automatically optimized when compiling your app: Bitmap files may be automatically optimized with lossless image compression by the aapt tool during the build process. For example, a true-color PNG that does not require more than 256 colors may

Large app size due to images. How to compress .PNG images?

由 为君一笑 提交于 2019-12-23 07:31:36
问题 I am developing an app which has a lot of images to work on due to which the size of my app has become very large. I want to compress or something like that to reduce the size of app. Any idea? 回答1: .png -files which are placed in the res/drawable are automatically optimized when compiling your app: Bitmap files may be automatically optimized with lossless image compression by the aapt tool during the build process. For example, a true-color PNG that does not require more than 256 colors may

How to change the background colour's opacity in CSS [duplicate]

由 好久不见. 提交于 2019-12-23 06:48:24
问题 This question already has answers here : How do I give text or an image a transparent background using CSS? (28 answers) Closed 3 years ago . I have a PNG file which I give a background colour to its transparent areas, but I would like to make the background colour a bit transparent, like opacity. Here is my code so far: social img{ opacity:0.5; } .social img:hover { opacity:1; background-color:black; } 回答1: background: rgba(0,0,0,.5); you can use rgba for opacity, will only work in ie9+ and

图像PNG格式介绍

由 蓝咒 提交于 2019-12-23 05:25:45
1 图像 png 格式简介 　　PNG是20世纪90年代中期开始开发的图像文件存储格式，其目的是企图替代GIF和TIFF文件格式，同时增加一些GIF文件格式所不具备的特性。流式网络图形格式(PortableNetwork Graphic Format，PNG)名称来源于非官方的“PNG’s NotGIF”，是一种位图文件(bitmapfile)存储格式，读成“ping”。PNG用来存储灰度图像时，灰度图像的深度可多到16位，存储彩色图像时，彩色图像的深度可多到48位，并且还可存储多到16位的α通道数据。PNG使用从LZ77派生的无损数据压缩算法。 2 图像 png 文件结构 　　PNG图像格式文件(或者称为数据流)由一个8字节的PNG文件署名(PNG filesignature)域和按照特定结构组织的3个以上的数据块(chunk)组成。 　　PNG定义了两种类型的数据块，一种是称为关键数据块(criticalchunk)，这是标准的数据块，另一种叫做辅助数据块(ancillarychunks)，这是可选的数据块。关键数据块定义了4个标准数据块，每个PNG文件都必须包含它们，PNG读写软件也都必须要支持这些数据块。虽然PNG文件规范没有要求PNG编译码器对可选数据块进行编码和译码，但规范提倡支持可选数据块。 3 图像 png 文件特性 　　PNG文件格式保留GIF文件格式的下列特性：

jQuery combine a selection of pngs to one image timeline animation

由 爷，独闯天下 提交于 2019-12-23 04:44:05
问题 Animation is difficult with GIF images due to white borders on text and other pixelation and dithering issues. So I have decided despite the lack of support for PNG on IE especially fadeIn or fadeOut jQuery effects on PNG causing black borders to do it. I have a folder like /cdn.com/ui/photo/1.png /cdn.com/ui/photo/2.png /cdn.com/ui/photo/3.png This is my HTML code, is there anway to add a delay or somehow loop and change the source of say 1-38 and keep looping it - maybe even customize the

Cropping image by the center

由 点点圈 提交于 2019-12-23 04:36:19
问题 I have a PNG image of size 218, 178. I am using matplotlib's function imread to convert it into a ndarray. I would like to crop it to get the middle 64X64 part of the image. I tried cropping with np.reshape, but it makes no sense. I also tried slicing as a normal array, but I can't get it right since the actual array has a shape of (218,178,3). I want it (64,64,3) taking from 77 to 141 and 57 to 121 for the first two dimensions. 回答1: You want to slice the first two axes of the numpy array,

Transparent PNG in a div tag, not using alpha?

由 蓝咒 提交于 2019-12-23 04:11:54
问题 I have an odd issue while beginning to learn CSS. This is a test page. It has a large transparent PNG covering the background color of solid blue. Typically the black image (which has transparent holes in it) completely blacks out my background color. In this example page I made the image's div transparent just to see if the background was still working. Any ideas why my alpha is getting completely ignored? Thanks all. 回答1: It's because on .backgrounddiv you have background-color set to #000

PIL: can't save the jpg pasted with a png

由 ﹥＞﹥吖頭↗ 提交于 2019-12-23 03:23:08
问题 I'm trying to paste a png on a jpg. Here is the code: #!/usr/bin/env python3 from PIL import Image from PIL import ImageDraw im = Image.open("existing.jpg") logo = Image.open("python-32.png") back = Image.new('RGBA', im.size) back.paste(im) poly = Image.new('RGBA', (512,512)) pdraw = ImageDraw.Draw(poly) pdraw.polygon([(128,128),(384,384),(128,384),(384,128)], fill=(255,255,255,127),outline=(255,255,255,255)) back.paste(poly, (0,0), mask=poly) back.paste(logo, (im.size[0]-logo.size[0], im

How to write a base64 decoded png image to file?

由 风流意气都作罢 提交于 2019-12-23 02:49:14
问题 I try to write a base64 png image to file with following code: imageReader := base64.NewDecoder(base64.StdEncoding, strings.NewReader(Images[i])) pngImage, _, err := image.Decode(imageReader) if err != nil { beego.Error(err) } bounds := pngImage.Bounds() if imgFile, err = os.Create(fileName + ".png"); err != nil { return Data{} } defer imgFile.Close() _, err = imgFile.Write([]byte(pngImage)) The bounds are ok. The error message for the last line is cannot convert pngImage (type image.Image)

jmeter jtl文件解析

由 寵の児 提交于 2019-12-23 02:46:31
Jmeter报告生成： 1．第一种在测试过程中直接用命令生成图标 在测试过程中将jtl转成测试报告(在jmeter的bin目录下执行) ./jmeter -n -t baidu_requests_results.jmx -r -l baidu_requests_results.jtl -e -o /home/tester/apache-jmeter-3.0/resultReport 参数说明： -n : 非GUI 模式执行JMeter -t : 执行测试文件所在的位置及文件名 -r : 远程将所有agent启动用在分布式测试场景下，不是分布式测试只是单点就不需要-r -l : 指定生成测试结果的保存文件， jtl 文件格式 -e : 测试结束后，生成测试报告 -o : 指定测试报告的存放位置 -o 指定的文件及文件夹，必须不存在 ，否则执行会失败，对应上面的命令就是resultReport文件夹必须不存在否则报错 2．利用插件，直接用工具打开jtl文件 下载的插件放在jmeter安装目录的lib/ext目录 3．第三种：使用之前的测试结果，生成测试报告 ./jmeter -g baidu_requests_results.jtl -e -o /home/tester/apache-jmeter-3.0/resultReport -g : 指定已存在的测试结果文件 -e ：测试结果后
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