Pico New Setting- Image Compression Quality

[gigamaster]

Pico New setting in Preferences - Image Compression Quality

Control Panel »» Pico »» Preferences

✅ Path for extra images (uploads / module instance), default value : uploads/pico
✅ Pixels for extra images (Article Header & Open Graph)
Default value : 1200x627 820x312 640x360
✅ Extra Image quality compression. Default value: 50

Example of upload :

🗻 photo2001x1328.jpg

Result :

image_0_[...md5...].jpg - 945x627 pixels - 40 ko
image_1_[...md5...].jpg -470x312 pixels - 16 ko
image_2_[...md5...].jpg - 542x360 pixels - 19 ko

NOTE

1. The images are resized with fixed Height - the Width is automatically resized with the same ratio. Also, in the ImageMagick version used to test image resize and compression, the default quality setting used is 85, but photo quality is not for webpage optimization, then a default value of 50..
2. CSS is used to make the generated image fit the article header.
3. XCL Themes use a Smarty condition for Open Graph image
   if module = pico, link to generated image, otherwise get default image of the website.

[gigamaster]

JPG anf PNG compression quality. From ImageMagick documentation :

For the JPEG and MPEG image formats, quality is 1 (lowest image quality and highest compression) to 100 (best quality but least effective compression).

For the MNG and PNG image formats, the quality value sets the zlib compression level (quality / 10) and filter-type (quality % 10). The default PNG "quality" is 75, which means compression level 7 with adaptive PNG filtering, unless the image has a color map, in which case it means compression level 7 with no PNG filtering.

For compression level 0 (quality value less than 10), the Huffman-only strategy is used, which is fastest but not necessarily the worst compression.

If filter-type is 4 or less, the specified PNG filter-type is used for all scanlines

More...
http://www.imagemagick.org/script/command-line-options.php#quality