07-08-2024, 08:12 AM
(This post was last modified: 07-08-2024, 08:31 AM by rich2005.
Edit Reason: edit
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(07-08-2024, 06:46 AM)gmpuser Wrote: I have added an image to try to show you what I mean.
https://imgur.com/0RUGIuf
The images I am using are black text on a white background. You can notice the difference after the conversion. If you zoom in, the converted image has extra distortion around the text and is not the same as the original.
I did test the Format and Compression and saved it as JPG set at 100. This improves the quality, but it is still not the same as the original. I tried converting to PNG with 0 compression, and this keeps the same image quality from what I can see.
I had a feeling yesterday, that small text might be involved. Jpeg compression artefacts. Even when jpeg quality is set to maximum, there is still compression. Jpeg is not lossless. This is some original text with the cropped version on top. Linear inverted colour to make the artefacts more visible. Toggle visibility on/off to see the two sets and finally difference mode to see all of them. https://i.imgur.com/z2FtOuZ.mp4 20 seconds so do not blink.
Quote: My original JPG files were from Photoshop, and an image was around 900 KB in size. The same image from the bimp plugin came out at 456 KB and with the JPG quality set to 100 is 733 KB so something is being removed. It may just be the cropped space reduceing the size. The PNG files are over 10 MB which is not ideal, but I do need to do further editing and can reduce this file size later with something like the RIOT tool.
PNG format is lossless. The png compression value changes the amount of effort involved in unpacking the file when it is opened. More compression, slower to open. There is also lossless tiff and if you want a smaller file size try webp which has both lossy and lossless options. RIOT will just strip out metadata then re-encode the jpeg and get a new set of compression artefacts.
Quote: I have also noticed the JPG files I have exported from Photoshop will not read in the BIMP Plugin. When I open directly in GIMP it is asking to import the Image from a color profile. I may need to save them in a different way from Photoshop.
That is strange. If you can post one of the original jpegs to check, (or maybe not 733 KB too large for an attachment) might help. PS is notorious for not following industry standards. I might pull out my old PS7 see if I can reproduce that.
Edit: Jpeg is really a finished format, not one to start editing with. Try exporting from PS as a tiff and leave the conversion to jpeg as the final procedure. The jpeg spec. does differentiate between greyscale and RGB. What mode your original images ?