All Questions
Tagged with imagemagick jpeg
16
questions
2
votes
2
answers
122
views
How to prevent large file size in JPEG-PDF roundtrip conversion?
TL;DR: File size doubled in roundtrip conversion between JPEG and PDF. Tools used : poppler and imagemagick
I am doing this
Extract images from a pdf containing only images (scanned document), via ...
1
vote
2
answers
1k
views
Remove jpeg artifacts for scanned texts
I have a scanned PDF of a textbook, but the PDF is aggressively compressed so lots of JPEG artifacts are present and affects its readability. Example:
I tried a variety of method to fix it but the ...
- 175
0
votes
2
answers
430
views
How do I reveal "hidden" image noise
Computer images can hide compression noise that's barely noticeable when looking directly at it, but if you tilt your laptop screen you see the noise, eg. the edges around the cans in this image.
...
- 2,087
3
votes
1
answer
7k
views
Changing the DPI in a JPEG without re-encoding? with ImageMagick or something else
Sometimes I have image files which I want to contain a certain DPI setting. Note that I mean just the DPI value, i.e. just the value in the image's metadata. I don't want to resize the actual image. ...
- 1,172
1
vote
1
answer
2k
views
Imagemagick changes page size when converting from pdf to jpg
I want to convert a pdf to jpg.
The page size is not standard.
(pdf here: imslp)
When I convert the pdf to jpg with
convert -density 300 sheet.pdf sheet.jpg, I get this: Converted image. (The ...
- 143
1
vote
1
answer
1k
views
Convert jpeg quality to 80% using automator
I want to make a automator script that goes trough a folder with subfolders and convert all .JPEG (or .JPG) to the same JPEG, but with a quality of 80%.
There is no option in Automator it self like ...
- 111
0
votes
2
answers
140
views
JPGs created with Imagemagick won't display on TV
I am trying to convert a free ebook from PNG to JPG, so I can read it on my Sony Bravia KDL-40R470.
This is how I converted the PNG file:
convert -density 117 -quality 80 progit.pdf progit.jpg
...
- 203
2
votes
1
answer
2k
views
Why does ImageMagick's montage limit the JPG output to 65500 instead of 65535?
JPEG/JFIF supports a maximum image size of 65535×65535 pixels. Is there any reason why ImageMagick's montage limit the JPG output to 65500 instead of 65535?
- 21.8k
1
vote
0
answers
202
views
Convert list of JPEGs to repeating animated gif using ImageMagick
I am using the convert command in ImageMagick to convert a list of JPEGs to one single animated GIF. The problem comes when the first frame keeps on repeating after every second within the gif which ...
user3417794
2
votes
1
answer
4k
views
Imagemagick killing colour quality when resizing image
I'm trying to resize a bunch (450+) of images through imagemagick, they all start at 500x500 and I've written a script to resize them to about 5 different sizes.
Now I've converted them I notice that ...
- 1,461
6
votes
2
answers
921
views
Automating the choice between JPEG and PNG with a script
Choosing the right format to save your images in is crucial for preserving image quality and reducing artifacts. Different formats follow different compression methods and come with their own set of ...
- 374
0
votes
3
answers
14k
views
How to batch-convert JPG files to uncompressed TIFF
I need to collect 1000 uncompressed TIFF files. I have a large set of JPG images, so I decided to convert them to TIFF format. The loss in quality is ok in this case for me.
I used the following ...
- 289
30
votes
4
answers
45k
views
How to convert a photo to a black and white image by ImageMagick?
How can I convert a JPEG photo to black and white (not grayscale) image like output of a FAX scanner, by ImageMagick?
- 3,074
4
votes
2
answers
6k
views
JPG files are too small when converted from PDF with imagemagick
I'm on Ubuntu 10.04 with imagemagick. I used this command:
convert myfile.pdf -density 300 file.jpg
This works well, but the JPGs are only about an inch high. How can I preserve the paper size in ...
- 41
0
votes
2
answers
400
views
Image to PDF quality
I am converting multiple jpg images to a single PDF using following command
convert *.jpg mybook.pdf
but the pdf quality is not good.
Is there a way to retain the original quality of images in ...
- 1,169