ppi

iPhone Screen Resolution. 160 vs 163 vs. the future

由 天涯浪子 提交于 2019-12-14 04:02:26
问题 I'm trying to make an app that displays something in real-world units. It's not a ruler app, but it wants that kind of precision. It already looks like the iPhone and iPod touch have different screen resolutions (160 & 163 respectively) I've found this Calculating pixel size on an iPhone and this iPhone screen resolution changes in future hardware and this http://forums.macrumors.com/showthread.php?t=350612 From my reading it sounds like I can treat the 320 * 480 screen space as 2 * 3.5

How can I find the pixel per inch value in a JPG image?

由 耗尽温柔 提交于 2019-12-13 07:37:27
问题 I am trying to validate certain images to not allow images lower than 300 pixels per inch, is there a way to find it on ASP.NET using C#? 回答1: You've got to read EXIF data from the image. Here you have an example of how you can do it, using ExifLib ExifLib - A Fast Exif Data Extractor for .NET 2.0+ Be warned that not all jpeg images have the resolution information. And, that even if they have it, you can print them using a completely different resolution. I.e. a pic 200px wide can be printed

Understanding points and the user space in Cocoa Drawing as they interact with screen resolution

由 ぃ、小莉子 提交于 2019-12-08 04:54:59
问题 Cocoa drawing sizes (widths & heights) are specified in points which are defined as follows in the OS X Cocoa Drawing Guide documentation: "A single point is equivalent to 1/72 of an inch" I understand from this that a point is a physical distance. So if my screen is 20 inches wide (for example) I would have 20 x 72 = 1440 points of horizontal width in points to work with. In other words, a point is independent of the resolution of the device. This does not seem to be so... A simple cocoa

Calculate PPI of Android Device

由 对着背影说爱祢 提交于 2019-12-05 17:07:54
问题 How do I calculate PPI of Android device. Most specifically Android Tablets. Take a Note that I want to calculate PPI of the device and not DPI. 回答1: It's easy like one-two-three =) Let's caculate PPI to Nexus 5 , for example. float LCD_Diagonal = 4.95f; int screenHeightPx = 1920; int screenWidthPx = 1080; float PPI = (float)Math.sqrt((double)(screenWidthPx*screenWidthPx + screenHeightPx*screenHeightPx))/LCD_Diagonal; Log.e(TAG, "display_page_screen_ppi: " + String.format(Locale.getDefault(),

零基础，史上最通俗视频编码技术入门

由 ☆樱花仙子☆ 提交于 2019-12-04 23:28:55
1、引言 如今我们所处的时代，是移动互联网时代，也可以说是视频时代。从快播到抖音，从“三生三世”到“延禧攻略”，我们的生活，被越来越多的视频元素所影响。 而这一切，离不开视频拍摄技术的不断升级，还有视频制作产业的日益强大。 此外，也离不开通信技术的飞速进步。试想一下，如果还是当年的56K Modem拨号，或者是2G手机，你还能享受到现在动辄1080P甚至4K的视频体验吗？ 除了视频拍摄工具和网络通信技术升级之外，我们能享受到视频带来的便利和乐趣，还有一个重要因素，就是视频编码技术的突飞猛进。 视频编码技术涉及的内容太过专业和庞杂，市面上的书籍或博客多数都只是枯燥的技术概念罗列，对于新手来说读完依旧蒙逼是常态，本文将借此机会，专门给大家做一个关于视频编码的零基础科普。 2 、图像基础知识 2.1 什么是像素？ 说视频之前，先要说说图像。图像，大家都知道，是由很多“带有颜色的点”组成的。这个点，就是“像素点”。 像素点的英文叫Pixel（缩写为PX）。这个单词是由 Picture(图像) 和 Element（元素）这两个单词的字母所组成的。 ▲ 电影《像素大战（Pixels）》，2015年 像素是图像显示的基本单位。我们通常说一幅图片的大小，例如是1920×1080，就是长度为1920个像素点，宽度为1080个像素点。乘积是2,073,600，也就是说，这个图片是两百万像素的。

Calculate PPI of Android Device

由 久未见 提交于 2019-12-04 02:58:53
How do I calculate PPI of Android device. Most specifically Android Tablets. Take a Note that I want to calculate PPI of the device and not DPI. It's easy like one-two-three =) Let's caculate PPI to Nexus 5 , for example. float LCD_Diagonal = 4.95f; int screenHeightPx = 1920; int screenWidthPx = 1080; float PPI = (float)Math.sqrt((double)(screenWidthPx*screenWidthPx + screenHeightPx*screenHeightPx))/LCD_Diagonal; Log.e(TAG, "display_page_screen_ppi: " + String.format(Locale.getDefault(),"%d %s", Math.round(PPI), "ppi")); In result we have 445 ppi that's true according with specs . PPI The

DPI in Retina iPad app design

由 大城市里の小女人 提交于 2019-12-03 11:24:31
问题 I don't know if this belongs in StackOverflow or some other SE site, but here goes. I have a PSD design I have an iOS development team turning into a Retina iPad app. However, this design is made in the default 72 dpi. The development team is now saying the design should be 264 dpi (same as a Retina iPad) -- as well as a 132 dpi version for the non-Retina edition. This confuses me, as I was under the impression that dpi just represents how many pixels go into an inch of output, and therefore

DPI in Retina iPad app design

由 北战南征 提交于 2019-12-03 01:45:21
I don't know if this belongs in StackOverflow or some other SE site, but here goes. I have a PSD design I have an iOS development team turning into a Retina iPad app. However, this design is made in the default 72 dpi. The development team is now saying the design should be 264 dpi (same as a Retina iPad) -- as well as a 132 dpi version for the non-Retina edition. This confuses me, as I was under the impression that dpi just represents how many pixels go into an inch of output, and therefore would only matter in printing. The dpi of an iPad just represents the number of pixels for each inch of

Cocoa Point vs Pixel and PPI

由 僤鯓⒐⒋嵵緔 提交于 2019-11-30 09:46:56
问题 Well, I have basically two questions regarding screen resolution in iOS devices. 1) In iOS documentation, on the Point vs Pixels section, it states the coordinates are passed in to framework as points, and that "One point does not necessarily correspond to one pixel on the screen." as found here: https://developer.apple.com/library/ios/#documentation/WindowsViews/Conceptual/ViewPG_iPhoneOS/WindowsandViews/WindowsandViews.html When they are different? Up until now I was assuming they were

Cocoa Point vs Pixel and PPI

由 主宰稳场 提交于 2019-11-29 16:44:16
Well, I have basically two questions regarding screen resolution in iOS devices. 1) In iOS documentation, on the Point vs Pixels section, it states the coordinates are passed in to framework as points, and that "One point does not necessarily correspond to one pixel on the screen." as found here: https://developer.apple.com/library/ios/#documentation/WindowsViews/Conceptual/ViewPG_iPhoneOS/WindowsandViews/WindowsandViews.html When they are different? Up until now I was assuming they were equal and passing in pixel coordinates. Is this a parameter that changes from device to device? 2) I'm also
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