I use Imagine library and I would like to know if is it possible to compress images with this library?
Other question:
Do you think it's a good solution to compress a lot (30 images) of images with the library in order to use a command line?
You can save the images with lesser quality to compress them:
To save at 50% quality:
$imagine->open('/path/to/image.jpg')->save('/path/to/image.jpg', array('quality' => 50));
And as for whether or not to do the compression at command line, you can do it but I don't recommend it. Image manipulation takes a lot of cpu and ram, so I suggest you download the images and manipulate them on your computer (not on the production server), or do it in a php script but limit the number of images to compress.
Related
How can I, using PHP, compress an image with Lossy/Lossless compression in a similar way that these two sites compress them:
https://compressor.io/ and https://kraken.io/web-interface
Thanks!
These websites don't compress images using PHP and you can't get a similar result by using PHP - They use different compression tools or plugins written specially to compress images.
To compress a PNG, the best solution is pngquant, but you have to install it on your server to use it with PHP.
Also, here is the list of tools you can check, about the compression of different type of images.
Yes, you can with this PHP API: PHP API for images
It's a set of tools for managing images where lossy optimization is included.
I'm wondering how to figure out the best compress rate (small filesize + no quality loss) automatically.
At the moment I'm using imagejpeg() with $quality = 85 for each .jpg.
PageSpeed (Chrome Plugin) suggests, to lower the quality of a few images to save some kb. The percentage of reduction is different.
I'd like to write a cronjob that crawls a specific directory and optimizes every image.
How does PageSpeed or TinyPNG figure out the best optimized quality and is this possible with PHP or another serverside-language?
TinyPNG uses pngquant.
Pngquant has option to set desired quality, similar to JPEG. You can run something like:
<?php system('pngquant --quality=85 image.png'); ?>
Pngquant website has example code showing how to use pngquant from PHP.
For JPEG you can apply lossless jpegcrush.
JpegMini (commercial) and jpeg-archive (free) are lossy and can can automatically find a minimal good quality for a JPEG.
In PHP you can roughly estimate how much JPEG was compressed by observing how much file size changes after re-compression. File size of JPEG recompressed at same or higher quality will not change much (but will lose visual quality).
If you recompress JPEG and see file size halved, then keep the recompressed version. If you see only 10-20% drop in file size, then keep the original.
If you're compressing yourself, use MozJPEG (here's an online version).
I process uploaded images by php to save (after resize) by imagejpeg. As I explored, imagejpeg is the best php command to compress jpg images to reduce the file size. However, when I check my website by Google Page Speed, it says all of my images can be compressed 4-10%.
What is the common method to compress images to meet the Google standard?
Googles "standard" is the possible maximum to be expected by google. You need to use highly optimized image compressors that does nothing else than image compressing and therefore get a possible maximum best value here.
You can for example, open you jpeg file in a image editor like adobe photoshop and create the possible maximum best compression to be expected by you while having visual control. Highly recommended.
The GD library provides a standard conform jpeg compression which should match a library users expectation, but which might not satisfy a graphic designer (and/or google by 4-10%).
My website is showing same image, one normal and other is blurred and I'm thinking what is better method of doing it in terms of speed. Create two images upon uploading where it uploads one normal image and one blurred to server or upload only one image but blur second one on the fly using gd?
If you're using GD, I would do it at upload and save them as flat files.
Apache and other web servers can serve flat files remarkably fast.
However, I would look into using http://www.graphicsmagick.org/ to do the image manipulation. It's much, much faster and efficient than Imagemagick and most certainly PHP's GD.
I'm wondering how to compress an PNG image correctly.
The situation is this :
I have a PNG image compressed and color-reduced with Irfanview on Windows. It's about 20KB.
When my portal software resizes (using magickwand 1.0.7) it with default values, it's about 63K (!).
Next try was to call MagickSetImageDepth($this->_imageHandler,8), resulting in a filesize of 34K, which is better, but still it's bigger than the (larger in dimension) original file.
None of the documented functions seem to fit to further compress the image.
Any hint would be greatly appreciated !
Greetz,
Sosa
PNG compression programs and routines use different techniques. I've found out that many times, an image that's already been compressed (or saved efficiently) cannot be compressed further or even has a higher file size as you are experiencing.
In your case I'd say your images cannot be compressed further, at least using MagickWand. You might just want to leave out that step.
Perhaps optimizing your PNGs before runtime would be a solution. There are many options available in this case. I've had luck with PNGGauntlet. You can run a batch job on PNGGauntlet and it will skip over the files that it would've made larger, if any.
Try this tool by Yahoo - it's great!
http://developer.yahoo.com/yslow/smushit/