png

问题 Anyone knows how to convert a bitmap to PNG or JPG using Objective C assuming I have CGImageRef imageRef; 回答1: UIImage *myImage = [UIImage imageWithCGImage:imageRef]; NSData *pngData = UIImagePNGRepresentation(myImage); NSData *jpgData = UIImageJPEGRepresentation(myImage); 来源： https://stackoverflow.com/questions/1740691/convert-bitmap-to-png-or-jpg-using-objective-c

问题 I'm trying to convert a batch of .ICO images over to .PNG images in Python. I have quite a few images to go through so I'd like to find a programmatic solution. I've tried using PIL but I can't seem to get the images and transparency to come out correctly. I'd prefer to use Python but if it can't be done another language or library would also help. 回答1: If it's just a batch job, why not just use imagemagick? 回答2: See http://code.google.com/p/casadebender/wiki/Win32IconImagePlugin It's a PIL

问题 I am using R in Jupyter, but unable to plot graphs in the notebook itself. Here is a reproducible example set.seed(123) mat = as.matrix(x = rnorm(100), y = rnorm(100)) plot(mat) In Jupyter: Error in png(tf, width, height, "in", pointsize, bg, res, antialias = antialias): unable to start png() device Traceback: If I use following, I can save the image in png format in current working directory. png('test.png') plot(mat) dev.off() Edit: SessionInfo() R version 3.4.4 (2018-03-15) Platform: x86

问题 I feel like I must be doing something silly wrong, but I just can't get this to work. This is the command I am running from cmd: inkscape.com "C:\path\ship.svg" -e --export-png="C:\Path\ship.png" --without-gui In return, I get: WARNING: File path "--export-png=C:\path\ship.png" includes directory that doesn't exist. It does exist. What am I missing? 回答1: -e and --export-png are the same argument, according to the docs. -e is just the short version. So you should use either one, but not both.

问题 I am using the JpegImagesToMovie.java to convert images to a .mov file. I was wondering if there was anyway I could edit this to work with .png files as the quality of the video is not very good and changing it would improve it. ImageIO.write(img, "png", new File("C:\\Users\\user\\Desktop\\tmp\\" + System.currentTimeMillis() + ".png")); ImageIO.write(img, "jpeg", new File("C:\\Users\\user\\Desktop\\tmp\\" + System.currentTimeMillis() + ".png")); ImageIO.write(img, "png", new File("C:\\Users\

问题 I'm looking for a way to Merge some PNG tile images into a big image. So I search and found some links. This is not answered properly. This is not tiling, it's good for overlaying images and this is not using WPF. So I'm making this question. Problem Definition: I have 4 PNG images. I want to merge them into a single PNG image, like this ------------------- | | | | png1 | png2 | | | | ------------------- | | | | png3 | png4 | | | | ------------------- Question: What is the best and efficient

问题 I'm trying to read a PNG image file written in 16-bit data type. The data should be converted to a NumPy array. But I have no idea how to read the file in '16-bit'. I tried with PIL and SciPy, but they converted the 16-bit data to 8-bit when they load it. Could anyone please let me know how to up out data from a 16-bit PNG file and convert it to NumPy array without changing the datatype? The following is the script I used. from scipy import misc import numpy as np from PIL import Image #make

问题 in my Winforms application which is connected to a database via Linq to SQL I am saving images (always *.png) to a table which looks like this: CREATE TABLE [dbo].[Images] ( [Id] INT IDENTITY (1, 1) NOT NULL, [Bild] IMAGE NOT NULL, PRIMARY KEY CLUSTERED ([Id] ASC) ); Before I can store a picture I have to convert it to byte[] and this is how I do it: public static byte[] ImageToByteArray(System.Drawing.Image imageIn) { using (MemoryStream ms = new MemoryStream()) { imageIn.Save(ms, System

问题 The bundling of JS and CSS files won't be necessary in HTTP/2, but what about image sprites? Looking at the demo it seems that it already works way faster than HTTP/1.1, but won't bundling images into sprites make it even faster? I mean, won't the PNG's optimization algorithms work better when all the data is in a single file? 回答1: It depends of your image(s) sizes and format. If the images are big enough, you won't gain much by using sprites, but for small images there are significant gains,

问题 I am able to insert JPG image into a PDF document with DCTDecode filter. I think the all parameters should be the same for PNG image too, except the filter which should be FlateDecode . However, when I try to insert PNG with the same parameters, the PNG image is not visible in he PDF document. UPDATE: I came to conclusion that the PDF file should include 1 0 obj << /Type /XObject /Subtype /Image /Width 512 /Height 512 /BitsPerComponent 8 /ColorSpace /DeviceRGB /SMask 9 0 R /Length 134753