31
votes
Accepted
Why does Google Chrome save a JPG image to WEBP instead?
File extensions are quite irrelevant for HTTP: if the server says Content-Type: image/webp, then it's a WebP image, period. (Compare to how most websites don't use .html in their URLs anymore even ...
- 465k
22
votes
Accepted
What's the difference between jpg and JPG on mac?
At a guess, one came directly from a camera, the others were saved by an application in the Mac itself.
There is no difference whatsoever in the file type itself, merely that one is a hangover from ...
- 50k
20
votes
Is it possible to change orientation of JPG image without rotating it (and thus losing information)?
JPG can be rotated using only EXIF data, so no re-encoding is necessary.
I found this tutorial on the orientation flag - JPEG Rotation and EXIF Orientation
These days, most image apps can handle this ...
- 50k
18
votes
Why does Google Chrome save a JPG image to WEBP instead?
CDN data traffic reduction
WebP is an image format currently developed by Google, based on technology acquired with the purchase of On2 Technologies.
If the User-Agent field in your HTTP(S) request ...
- 2,195
12
votes
Accepted
Changing the DPI in a JPEG without re-encoding? with ImageMagick or something else
You can do this with exiftool.
You command would be:
exiftool -XResolution=# -YResolution=# FileOrDir
Change the hashmark to the new DPI number. This command will make backups of each file, which you ...
- 1,489
11
votes
How do I edit a JPEG's EXIF data with Gimp?
As of Gimp 2.9.4 (possibly 2.9.2) there is a built-in metadata editor/viewer. It is under the menu > Image > Image Metadata.
See http://libregraphicsworld.org/blog/entry/gimp-gets-advanced-exif-xmp-...
- 284
11
votes
Accepted
Is it safe to simply rename a .jfif file to .jpg?
Yes.
JPEG is not a file format - it's a compression method. It doesn't specify how the compressed data should be stored in a file. There are two file formats that fill in this gap: the original JFIF, ...
- 57.5k
10
votes
What's the difference between jpg and JPG on mac?
This is just how the files were created.
Someone, or some piece of software, chose to use .JPG in some cases and .jpg in others.
That's it. It doesn't mean anything.
- 3,076
8
votes
Removing Background color in Paint.net
There are multiple ways to accomplish this, but below are two of the easiest ways. The end results are more or less equivalent, so try both to see which one looks better to you.
Use Color to Alpha ...
- 747
8
votes
How to disable WebP images in Chrome?
Open-source solutions
WebP is an image format currently developed by Google, based on technology acquired with the purchase of On2 Technologies.
If the User-Agent field in your HTTP(S) request header ...
- 2,195
7
votes
How can I tell if a JPEG was saved as Progressive?
If you're on a unix, use the file command:
$ file image.jpg
image.jpg: JPEG image data, Exif standard: [TIFF image data, little-endian, direntries=0], progressive, precision 8, 2000x1200, components 3
- 71
7
votes
How to disable WebP images in Chrome?
Method 1 provided by @Darius half works, but needs to be combined with a second modification. Changing the User-Agent alone does not fully solve the problem as the image server may also look at the ...
- 171
7
votes
Accepted
how to put an image in an HTML signature for Thunderbird?
The url of the img is only valid to your computer and it is not valid at the receiver side. So you need to encode the image file using a base64 encoder like this one.
Upload the signature and ...
- 1,829
6
votes
Accepted
Is TIFF with JPEG compression lossy?
TIFF files can be compressed OR uncompressed.
Using JPEG compression on a TIFF is certainly lossy.
However if you have the option to use LZW compression on a TIFF, that is lossless. As of course is ...
- 630
6
votes
Accepted
CIFS mounted on Linux from Windows shows corrupt/distorted images
There is a known bug with the version of Apache2 (2.4.25 Debian) I am using that serves the CIFS files in a funny manner causing the file corruption. For those using Apache2 you will likely be dealing ...
- 101
5
votes
Accepted
Converting NEF files to JPEG
You can do it with IrfanView. Do the following:
Download IrfanView
Download the Formats plugin. Note that if you downloaded the x64 version of IrfanView, you will need to download the x64 plugin. ...
- 1,254
5
votes
How to disable WebP images in Chrome?
I found a possible solution to this. I simply added a question mark (?) to the end of the url and was able to download the image. So for example:
https://www.fritolay.com/sites/fritolay.com/files/2019-...
5
votes
Can PNG images contain embedded thumbnails like JPG files?
You can put a thumbnail image in the Exif profile, then store the Exif profile in a PNG eXIf chunk, if you are using libpng-1.6.32 or later.
5
votes
Accepted
Create video from bunch of JPEGs
If you rename the images to be consecutively numbered, then you can use
ffmpeg -y -framerate 1 -i <path>\%06d.jpg -r 5 -c:v libx264 -pix_fmt yuv420p <path>/video.mp4
Consecutively ...
- 37.1k
5
votes
How to use dcmcjpeg to convert DICOM to JPEG?
Please use the tool dcmj2pnm:
This tool converts DICOM images to PGM/PPM, PNG, TIFF, JPEG or BMP
Here is a usage sample:
dcmj2pnm --write-jpeg --min-max-window ST1-SE1.dcm foot-xray.jpg
Use the ...
- 103
5
votes
Is converting images to pdf lossy?
PDF is a container format, not an image format. Thus it should be possible to embed an image into a PDF, and then subsequently extract it, without recompression. However, ImageMagick convert does ...
- 1,937
4
votes
How to generate an EXIF thumbnail for a JPEG?
The task can be completed with exiftool (for updating EXIF) and ImageMagick (for crating thumbnails).
First let's download and install/extract both programs. Put exiftool to any folder and include it ...
- 278
4
votes
Batch converting PNG to JPG in linux
Many years too late, there's a png2jpeg utility specifically for this purpose, which I authored.
Adapting the code by @Marcin:
#!/bin/sh
for img in *.png
do
filename=${img%.*}
png2jpeg -q ...
- 216
4
votes
Converting NEF files to JPEG
I shoot in RAW with my Nikon D3100 and used the following to convert images to JPEG format (Ubuntu): "Working with RAW Files" section of this page.
The page shows an example using pnmtopng, which ...
- 66
4
votes
Accepted
JPEG size made smaller by MSPAINT, why?
Even as you can't tweak a quality value when you save a jpg file in MS PAINT, it applies a default value that it's unknown (around 75% - 85%). This value will degrade the quality and reduce the size ...
- 17.6k
4
votes
Accepted
Whatsapp web does not accept jpg file in portrait orientation
Open the photo in an editor (I used Picasa) and save a copy. The portrait photos from my Canon EOS camera are rejected by Whatsapp Web, but once I open and save them, everything was fine.
Do submit ...
4
votes
Reading animated JPEG ("MVIMG_") in Windows 10
So apparently this is a custom file format consisting of a JPEG image and a MP4 video.
I found this GitHub repository containing a Bash script to extract the video part of the file.
Because the (...
- 63.9k
4
votes
How to convert multiple images at once from JPEG to PNG?
What you are looking for is an image conversion software that supports batch conversion, aka batch processing.
Some conversion software has batch conversion built in. Alternatively, you can write a ...
- 23.2k
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