jpeg

VsampFactor and HsampFactor in FJCore library

I've been using the FJCore library in a Silverlight project to help with some realtime image processing, and I'm trying to figure out how to get a tad more compression and performance out of the library. Now, as I understand it, the JPEG standard allows you to specify a chroma subsampling ratio (see http://en.wikipedia.org/wiki/Chroma_s...

Problem reading JPEG image using ImageIO.read(File file)

Hi, I'm having problems reading this one JPEG file using ImageIO.read(File file) - it throws an exception with the message "Unsupported Image Type". I have tried other JPEG images, and they seem to work fine. The only differance I've been able to spot is that this file seems to include a thumbnail - is that known to cause problems wit...

Some JPEG images are not working in IE

Hello, I have a press archive. The press archive displays automattically created thumbnails as links to a PDF document. This is what i get in IE 6, 7 & 8: While it works fine in Chrome: The thumbnails are automatically created by imagemagick: $cmd = 'convert ' . $_FILES['file']['tmp_name'] # This is a PDF file . '[0]' #...

Parsing JPEG file format: Format of entropy-coded segments (ECS) ?

I'm having difficulty understanding the ITU-T T.81 spec for the JPEG file format. Hopefully someone else here has tried to parse JPEG files and/or knows about the details of this file format. The spec indiates that the ECS0 segment starts after the SOS segment but I can't find where in the spec it actually talks about the format of the ...

Is PNG the most economically sound file format to store pictures in?

I am looking for an economically sound solution to store pictures long time. I read about the PNG file format that it has superior characteristics compared to JPEG, namely in these categories: no patents, no licenses, no royalities no quality loss yet compressed I have a lot of big ESP's from PhotoShop that contain tons of metadata,...

Handling Corrupted JPEGs in C#

We have a process that pulls images from a remote server. Most of the time, we're good to go, the images are valid, we don't timeout, etc. However, every once and awhile we see this error similar to this: Unhandled Exception: System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI+. at System.Drawing.Image....

include figure files in latex

Hi, I am trying to include jpeg files in latex \includegraphics[width=57.6mm, height=43.2mm]{../../results2/html/zerooneloss_stumps.jpg} With specified the width and height and compiled with pdflatex, however, it produces the error: ! LaTeX Error: Cannot determine size of graphic in ../../results2/html/zerooneloss_stumps.jpg (no B...

Large number of soft page faults when assigning a TJpegImage to a TBitmap

I have a Delphi 6 Pro application that processes incoming jpeg frames from a streaming video server. The code works but I recently noticed that it generates a huge number of soft page faults over time. After doing some investigation, the page faults appear to be coming from one particular graphics operation. Note, the uncompressed bit...

Javascript render jpeg binary data from variable

How to render JPEG/PNG file data contained in Javascript variable? Is it possible ? What javascript libraries needed ? Browser in use is FF / IE. Thanks ...

Resizing JPEG image during decoding

I'm working on a program that creates thumbnails of JPEG images on the fly. Now I was thinking: since a JPEG image is built from 8x8-pixel blocks (Wikipedia has a great explanation), would it be possible to skip part of the decoding? Let's say that my thumbnails are at least 8 times smaller than the original image. We could then map eac...

Fast or asynchronous AS3 JPEG encoding

I'm currently using the JPGEncoder from the AS3 core lib to encode a bitmap to JPEG var enc:JPGEncoder = new JPGEncoder(90); var jpg:ByteArray = enc.encode(bitmap); Because the bitmap is rather large (3000 x 2000) the encoding takes a long while (about 20 seconds), causing the application to seemingly freeze while encoding. To solve...

ActionScript 3 Read JPEG quality

I am developing image uploader for Flash 10. Is there a way to read jpeg quality of the browsed images. ...

Getting Image size of JPEG from its binary

Hi I have a lot of jpeg files with varying image size. For instance, here is the first 640 bytes as given by hexdump of an image of size 256*384(pixels): 0000000: ffd8 ffe0 0010 4a46 4946 0001 0101 0048 ......JFIF.....H 0000010: 0048 0000 ffdb 0043 0003 0202 0302 0203 .H.....C........ 0000020: 0303 0304 0303 0405 0805 0504 0405 0a07 ...

C: WinAPI CreateDIBitmap() from byte[] problem

I have been working on this problem for a while now. I am trying to add JPEG support to a program with libjpeg. For the most part, it is working fairly well, But for some JPEGs, they show up like the picture on the left. Original Image It may not be obvious, but the background shows up with alternating red green and blue rows. If any...

RMagick returns nil reading JPEG

When I try to open a JPEG format file in Rails using RMagick, it always return nil with any jpg file. Other file formats open well. $ script/console Loading development environment (Rails 2.3.4) >> require 'RMagick' >> img = Image.read("1.gif").first => 1.gif GIF 230x100 230x100+0+0 PseudoClass 256c 8-bit 2kb >> img = Image.read("1.png"...

JPG File Size Optimization - PHP, ImageMagick, & Google's Page Speed

I have photo gallery code that does image re-sizing and thumbnail creation. I use ImageMagick to do this. I ran a gallery page through Google's Page Speed tool and it revealed that the re-sized images and thumbnails both have about an extra 10KB of data (JPEG files specifically). What can I add to my scripts to optimize the file size?...

Can a BufferedImage be written to file any format?

Is it correct that if we have a BufferedImage object in java, we could potentially write it out in ANY format using ImageIO.write (if we have a Writer object for the same)? I tried writing a BufferedImage object into a jpg file, it outputted an empty image file however when i tried writing it in to a png file, it worked fine. ...

Java: Reading images and displaying as an ImageIcon

I'm writing an application which reads and displays images as ImageIcons (within a JLabel), the application needs to be able to support jpegs and bitmaps. For jpegs I find that passing the filename directly to the ImageIcon constructor works fine (even for displaying two large jpegs), however if I use ImageIO.read to get the image and ...

progressive jpeg flash

hello, I read your topic about jpeg progressive and AS3, I didn't test anything.. But, did you find a good solution for this problem? with a rendering like jpeg progressive? thank you for your response Best regard ...

What container is easiest for combining JPEGS and MP3s as video?

So I have N (for example, 1000) JPEG frames and 10*N ( for example, 100) seconds of MP3 sound. I need some container for joining them into one video file (at 10 frames/second) (popular containers like FLV or AVI or MOV are better). So what I need is an algorithm or code example of combining my data into some popular format. The code exa...