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Questions tagged [jpeg]

JPEG is a common lossy compression method for digital images. Use this tag for questions about JPEG images using the image/jpeg MIME type.

JPEG is a common lossy compression method for digital images. Use this tag for questions about JPEG images using the image/jpeg MIME type.

See also , , and for other image file formats with JPEG in the name.

More information at the JPEG Wikipedia page.

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How to convert PNG to JPG (client-side), and back to PNG (server-side), preserving full and semi-transparent pixels?

I'm writing an application in HTML5 + JS, and at some point I need to upload the contents of a element, which has some PNG file drawn on it. So I'm doing: $('#img').val(canvasElement.toDataURL()); As You can see, I provide no arguments to…
kremuwa
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How to reduce file size using PHP and JPEGs

I am using a the standard PHP functions imagecopytruecolor and imagejpeg to rescale and produce uploaded images from a standard HTML form. The images appear at the correct size however the image filesize is quite high (e.g. 540px * 350px =…
Mazatec
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Perl: saving cover from MP3 ID3-Tags in external JPG file

Im trying to save the image data from am id3 tag to an jpg file My actual script reads the image data and writes it to a file, whichs code looks exact like the original image file, but if i open it it looks like…
communications
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Poor Image Quality Inserting Google Charts into a PDF using JSPDF

I'm trying to render a pdf view of a reporting page that contains google charts to display my data. Currently I am going converting the chart to a url encoded JPEG. The image quality at this stage is still good but once i add it to the pdf document…
Matt Spurgeon
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Why do my images get clipped when served by this Perl CGI script?

When I try to print an image to STDOUT in a Perl CGI script, the image gets clipped when viewed in the browser. Here is the following code: if ($path =~ m/\.jpe?g$/i) { my $length = (stat($path))[7]; $| = 1; print "Content-type:…
Jeremy Gwa
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Compose multiple JPEG files without re-compression

How can I compose (adjoin) multiple JPEG files without re-compression? I know there is jpegtran that can losslessly crop and resize JPEG images, so I wonder if there is similar tool to adjoin images lossless? Their size is a multiple 1 MCU block…
sanmai
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Can iTextSharp generate PDF with JPEG images that are multi-stage filtered (both DCTDecode and FlateDecode)?

Recently I am tasked with reducing the file sizes of PDF generated from blank office documents. The images are mostly blank, but they have a variety of company letterheads (in color), borders and footers. Some are generated by software (and…
rwong
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Not able to set compression mode to JPEG-LS in JAI

I am using JAI 1.1.3 for windows and configured Build path to include jai_codec , jai_core and jai_imageio jars. When i try to write a image with JPEG-LS mode i get the error. Do i need to do any other configuration for JAI. import…
mizzo
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PHP: Converting png's and gif's into grayscale

im using the following script to convert jpgs into grayscale-images. http://bubble.ro/How_to_convert_an_image_to_grayscale_using_PHP.html i want to upgrade it to also convert pngs (with transparency) and gifs (with transparency) into grayscale…
matt
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Optimal JPEG compression for frames extracted from video

I have a small mp4 of a 6 second vine video. The total size on disk is about 840kb. I wrote a little script to extract the frames at 20fps as JPEG (with compression quality of 0.8). After running the script I got about 130 JPEGs around 22kb each.…
Ray
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Http PUT Request to jpeg

I received HTTP PUTs like: PUT /photo HTTP/1.1 X-Apple-AssetKey: F92F9B91-954E-4D63-BB9A-EEC771ADE6E8 X-Apple-Transition: Dissolve Content-Length: 462848 User-Agent: MediaControl/1.0 X-Apple-Session-ID: 1bd6ceeb-fffd-456c-a09c-996053a7a08c
paulgavrikov
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storing information in png and jpg

I have found a number of resources but nothing that has quite helped me with what I am looking for. I am trying to understand the .png and.jpg file formats enough to be able to modify and/or read the exif or other meta data in the files or to create…
user2097211
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Hidden/Open words in an Image file such as PNG or JGP

As far as I can tell my question is not related to topics involved in Stenography or in the win.rar soluations I've seen to this where you are essentially hidding messages. I am trying to figure out if there is a way to insert code into a file such…
user2097211
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Convert JPG/PNG to SVG format using PHP

How do I convert JPG/PNG to SVG using PHP? I know that it will not be vectorised, but I need it in a SVG-format. I dont want to use any other software than PHP. Something like this:
user1087110
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How to output unicode characters and lines into an image file?

I want to create a jpg or any other image format files for chinese characters, how do i do it? My input textfile (in utf8) looks like this: 阿贝•斯兰尼\t是\t美国人 Reading it is simple, i could simply do…
alvas
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