compression

问题 I have an image of a person and I want to compress it to make it less than 4KB. I need to compress it and still have the face of the person recognizable even if the image will shrink. 回答1: Here is Theresa May at 142kB: and resized to 72x72 and converted to greyscale and reduced to 2kB with ImageMagick at the command line: convert original.jpg -resize 72x72 -colorspace gray -define jpeg:extent=2kb result.jpg I can still recognise her. Here is some other guy reduced to 1kB and I can still

问题 Correct me if I'm approaching this wrong, but I have a queue server and a bunch of java workers that I'm running on in a cluster. My queue has work units that are very small but there are many of them. So far my benchmarks and review of the workers has shown that I get about 200mb/second. So I'm trying to figure out how to get more work units via my bandwidth. Currently my CPU usage is not very high(40-50%) because it can process the data faster than the network can send it. I want to get

问题 How do you compress a directory in Squeak Smalltalk? I found the compressFile method in StandardFileStream but I can't figure out how to compress multiple files or a directory. I experimented with the System-Compression classes but haven't had much luck. Thanks in advance! This is what I have now. I'm adding time stamps at the end of file names, so here I want to put all files that begin with the given file name into a zip or gzip file. compressFile: aFileName in: aDirectory | zipped buffer

问题 I'd like to pre-compress my static assets (excluding images) and serve them. To serve the public folder, I have: app.use(express.static('path/to/public/')); I believe express.compress() compresses on-the-fly, which seems like an unnecessary burden on the server CPU for static assets. What's the canonical way to achieve this? 回答1: The connect-gzip-static module seems to do this. I haven't tested it yet. It doesn't support dynamically decompressing assets where the client doesn't support

问题 Is there a better data type to be using to store a zlib compressed string in Postgresql? 回答1: Use bytea "The bytea data type allows storage of binary strings" 回答2: Use a bytea. Zip compressed data is not a text. 来源： https://stackoverflow.com/questions/2958073/postgres-text-column-doesnt-like-my-zlib-compressed-data

问题 I am looking to connect to Firebird Server 3.0 using WireCompression. This being new feature since version 3.0 I'm having a hard time to get it to do so and the only documented instructions I can find is setting WireCompression to TRUE in firebird.conf and use the connect parameter "wirecompression=true". This is what I've got this far: firebird.conf: # Firebird configuration file for Firebird 3.0 64-bit SuperServer # Optimized by IBSurgeon (www.ib-aid.com) for HQbird distribution. #

问题 Itroduction I'm currently working on John Conway's Game of Life in js. I have the game working (view here) and i'm working on extra functionalities such as sharing your "grid / game" to your friends. To do this i'm extracting the value's of the grid (if the cell is alive or dead) into a long string of 0's and 1's. This string has a variable length since the grid is not always the same size. for example: grid 1 has a length and width of 30 => so the string's length is 900 grid 2 has a length

问题 How can I accomplish this? A programmatic solution (Objective-c) is great, but even a non-progarmmatic one is good. I have pixelmator -> But that doesn't give you the option. I can't seem to do it with Preview either. I have tried googling, but haven't been able to find a solution so far. The only tool I have been able to use to do this is TexturePacker, but that creates a sprite sheet. 回答1: You can use libpng to convert the PNG image to three-byte (8:8:8) RGB. Then you can downsample to the

问题 How can I determine whether a string was compressed with gzcompress (aparts from comparing sizes of string before/after calling gzuncompress, or would that be the proper way of doing it) ? 回答1: A string and a compressed string are both simply sequences of bytes. You cannot really distinguish one sequence of bytes from another sequence of bytes. You should know whether a blob of bytes represents a compressed format or not from accompanying metadata. If you really need to guess programmatically

问题 I am wanting to compress results from QUERYS of the database before adding them to the cache. I want to be able to compress any reference type. I have a working version of this for compressing strings.. the idea based on scott hanselman 's blog post http://shrinkster.com/173t any ideas for compressing a .net object? I know that it will be a read only cache since the objects in the cache will just be byte arrays.. 回答1: This won't work for any reference type. This will work for Serializable