Color difference between original and thumbprints

[BassieXL]

All,

I noticed that generated thumbnails of some pics have a different "color-tone" than the original photo.

I did some experiements with one photo, of which the "color-tone" was severely incorrect. In Lightroom I exported the same photo with all different "color spaces" available (sRGB, AdobeRGB, ProPhotoRGB, P3, and a few more). It appears that the thumbnail of EACH of these files has a different tone, ranging from gray-ish pale to near-vibrant. The sRGB thumnail probably has the best result, but it still has a visually different color-tone than the original sRGB .jpg file.

Although with this, it seems that the "color space" is the culprit, most photos in the catalogue appear to be imported fine. Looking at the color space (or color space mode) exif-data, I cannot determine which setting causes the thumbprints to be off-tone.

I've been playing with the "JPEG Quality" and "JFile Thumbnail Creation" under Global Configuration \ Phoca Gallery \ Thumnails\ Thumbnail Generation Settings, without result.

Of course, I'd like the thumbprints to match as close-as-possible the original picture. Any recommendations for best results? A configuration option Phoca, or an export option in Lightroom?

Using Phoca Gallery v5.0.2, on Joomla 5.1.3

thx
BassieXL

[Jan]

Hi, there is no configuration for this in Phoca Gallery. Images (thumbnails) are created on your server with help of PHP and GD library. So the only options is to somehow change options for GD library on your server (no experiences there ) or maybe directly change the PHP code in Phoca Gallery and add some specific GD function to code:

https://www.php.net/manual/en/ref.image.php

which can somehow work with color tone

Jan

[BassieXL]

Hi Jan,
Thanks for response.

I'll have a look at the GD library for information.
Changing configuration in the GD library itself is probably a little beyond my skill set, but it might still be a good lead understand the behavior of the "Thumbnail engine" better. Maybe it'll help me to prepare the pics in such a manner that they'll be processed correctly.

thx again

Bassie

[Rizwan867]

To ensure thumbnails match the original photo's color tone:

Use sRGB Color Space: Ensure both your original image and thumbnails are consistently using the sRGB color space, as it's widely supported for accurate color representation.

Check Export Settings: In Lightroom, export your photos in sRGB color space to maintain consistency.

Adjust Thumbnail Settings: In Phoca Gallery, verify the "JPEG Quality" and "Thumbnail Creation" settings, and experiment with different values to see if they improve color consistency.

Calibration: Ensure your monitor is calibrated correctly to avoid discrepancies in color appearance.