Use Processes. GDI+ blocks per process a lot of ways. Yep, a pain, but there’s no way around it. Fortunately with tasks like this one (and any one that processes files on the filesystem), it’s too easy to just split the workload up between multiple processes. Fortunately it looks like GDI+ is using locks, not … Read more
I found a solution now, that works, at least if my resulting image is also a JPEG: First I read the image (from byte array imageData), and most important, I also read the metadata. InputStream is = new BufferedInputStream(new ByteArrayInputStream(imageData)); Image src = null; Iterator<ImageReader> it = ImageIO.getImageReadersByMIMEType(“image/jpeg”); ImageReader reader = it.next(); ImageInputStream iis = … Read more
See this solution. https://github.com/nbadal/android-gif-encoder It’s an Android version of this post. http://www.jappit.com/blog/2008/12/04/j2me-animated-gif-encoder/ To use this class, here is an example helper method to generate GIF byte array. Note here the getBitmapArray() function is a method to return all the Bitmap files in an image adapter at once. So the input is all the Bitmap files … Read more
The JPEG standard does not require that decoder implementations produce bit-for-bit identical output images. Unfortunately the standards document specifying decoder requirements, ISO 10918-2, is apparently not freely available online but Wikipedia says: …the JPEG standard (and the similar MPEG standards) includes some precision requirements for the decoding, including all parts of the decoding process (variable … Read more
I know you found the solution, but this might help anyone else that s looking for the same thing! I modified a class that I found here (thanks debers). And all the references to IPTC tags can be readed from this PDF And now the code (PHP >= 5.4): <? define(“IPTC_OBJECT_NAME”, “005”); define(“IPTC_EDIT_STATUS”, “007”); define(“IPTC_PRIORITY”, … Read more
Install Android NDK. Following instructions were verified with r8b, older versions may have problems, I don’t know. Get the Android sources for libjpeg-turbo from Benjamin Gaignard: git clone git://git.linaro.org/people/tomgall/libjpeg-turbo/libjpeg-turbo.git -b linaro-android In the libjpeg-turbo directory created by git, edit file Android.mk: after line 70, LOCAL_MODULE := libjpeg, add the following: ifeq ($(notdir $(MAKECMDGOALS)),libjpeg.a) LOCAL_SRC_FILES += … Read more
The jpeg uses a lossy compression method to achieve smaller file sizes. Unfortunately, that very method directly affects the value of (some) pixels, thereby destroying the information the way you have embedded it. You need to save the file in a lossless format to avoid this problem, such as bmp or png. Jpeg steganography is … Read more
Several options: You can check for the file extension: static bool HasJpegExtension(string filename) { // add other possible extensions here return Path.GetExtension(filename).Equals(“.jpg”, StringComparison.InvariantCultureIgnoreCase) || Path.GetExtension(filename).Equals(“.jpeg”, StringComparison.InvariantCultureIgnoreCase); } or check for the correct magic number in the header of the file: static bool HasJpegHeader(string filename) { using (BinaryReader br = new BinaryReader(File.Open(filename, FileMode.Open, FileAccess.Read))) { UInt16 … Read more
Edit: Version 1.5.0 (July 2017) of the Extensions to the PNG 1.2 Specification has finally added an EXIF chunk. It remains to be seen if encoders-decoders begin to support it. Original: PNG does not embed EXIF info. It allows, however, to embed metadata “chunks” inside the image. Some of the standardized chunks correspond to a … Read more
Nowadays this is pretty simple. The basic idea is: SVG to canvas canvas to dataUrl trigger download from dataUrl it actually works outside of the Stack Overflow snippet var btn = document.querySelector(‘button’); var svg = document.querySelector(‘svg’); var canvas = document.querySelector(‘canvas’); function triggerDownload (imgURI) { var evt = new MouseEvent(‘click’, { view: window, bubbles: false, cancelable: … Read more