• Learning notes: canvas with high definition screen


    There is a window property calleddevicePixelRatioThe ratio of physical pixels to CSS pixels of the device at that time can be calculated.Grammar: value = window.devicePixelRatio; Then the canvas is drawn by multiple, and then scaled by CSS to achieve the effect of high definition.Usage: /** @type {HTMLCanvasElement} */ let canvas = document.getElementById(“canvas”) let ctx = […]

  • CSS pixel and mobile terminal different screen adaptation problem


    Pay close attention to “learning front end seriously” Join us to study together and make progress every day This article starts with WeChat official account. pixel resolving power What we usually call the display resolution is actually the resolution set on the desktop, not the physical resolution of the display. But now LCD has become […]

  • Implementation of H5 mobile terminal image clipping with canvas


    Not long ago, we launched an H5 activity page on Chinese Valentine’s day. We need to do a local image clipping and uploading function to generate some specific confession images. Mainly used H5FileApiandCanvas. I feel that the image cutting function is very practical, so write an article to share. Demo address:https://github.com/Bless-L/im…Effect GIF: PS: This demo […]

  • What is dip of LCD


    Is the abbreviation of density independent pixel, which refers to the abstract sense of the pixel. It’s related to the screen density of the device. It’s a unit in Android. Dip and DP are the same. The official statement of Google is as follows:    Density-independent pixel (dp)   A virtual pixel unit that you should […]

  • Deep learning concept receptive field


    Link to the original text: https://blog.csdn.net/doufangzheng/article/details/104023161 catalogue preface Receptive field computing one-dimensional two-dimensional Effective receptive field Intuitive understanding Theoretical proof Effective receptive field The distribution of effective receptive field is different for different activation functions Effect of training on effective receptive field other How to deal with Gaussian distribution of sensing field effectively reflection Anchor […]

  • The tail is processed as a time series to identify whales


    By Lamothe ThibaudCompile FlinSource: to ward data science Using curvature integral and dynamic time warping, let’s study sperm whale recognition in depth! preface Recently, we tried Capgemini’s global data science challenge. I worked with ACORES whale research center to identify sperm whales and use AI to help save their lives. To accomplish this task, we […]

  • Seam carving algorithm: a seemingly impossible method of image size adjustment


    By samarendra Chandan Bindu dashCompile FlinSource: analyticsvidhya introduce In this article, we’ll delve into an interesting algorithm called seam carving. It seems impossible to adjust the size of an image without clipping or distorting its content. We will build step by step and implement the seam carving algorithm from scratch, while looking at some interesting […]

  • Zooteam front end weekly No.104


    Zooteam front end weekly No.104 For more previous tabloids, please visit:https://weekly.zoo.team After two years, webpack 5 is officially released! Since the release of webpack 4 in February 2018, there has been no further major update to webpack. In order to maintain the consistency of API, the old architecture has not changed much, leaving a lot […]

  • Canvas + webgl Chinese word art rendering


    The author wrote another articlehttps://segmentfault.com/a/11…This paper introduces the implementation of the text editor “simple poem” based on canvas, in which the text is rendered by webgl. This paper mainly describes the process of obtaining font data by canvas, stroke segmentation and analysis, and rendering effect by webgl. introduction It is easy to draw text with […]

  • Mobile terminal image upload step pit record (including translation, zoom, rotation and cutting)


    Bug1.ios upload picture clockwise rotation 90 degrees problem Solution 1. Use exif.js Get the current shooting angle of the picture and display it after correction http://www.mamicode.com/info-…http://blog.csdn.net/linlzk/a… Incorrect cutting position Solution 2. Offset left or offset top need to subtract the difference of translate http://tgideas.qq.com/webplat…Problem Description:When the target element’s superior element has transform:translate (x, y), using […]

  • Basic knowledge of canvas


    1、 Basic knowledge of canvas: 1. Basic knowledge Code examples var canvas = document.getElementById (‘canvas’) // gets the canvas element context = canvas.getContext (‘2d ‘); // get the drawing environment, indicating 2D //1. Basic knowledge context.fillStyle=’rgb(0,255,0)’; context.fillRect(0,0,200,200); 2. Lines context.lineWidth =5; // line width context.beginPath(); context.moveTo(40,40); context.lineTo(340,40); context.closePath(); context.stroke (); // draw outline 3. Round […]

  • Introduction to OpenCV image


    Introduction to image processing An image is made up of pixelsImage classification: binary image, gray image, RGB imageChannel order in opencv: B, G, R Read pixel Return value = image (position parameter)Gray image, return gray valueBGR image, the return value is the value of B, G, R # eg: p = img[88, 142] print(p) Returns […]