Guys, please take away this simple doubt that torments me kkk.
When I export a JPG image without any editing (the way I imported it was exported),
for some reason the exported image doesn't stay with the same size (in bytes) of the imported image.
In fact, the exported image gets even bigger.
The original image is 3.92 MB, 96 DPIAfter exporting with Corel it is 12.3 MB, 96 DPI
As I said before, I did not do any editing on the image to justify such an increase in the size (in Bytes) of the exported file.
Why can't the imported image (the original) and the exported image (which was not edited) have the same quality and size in bytes?
I also made a video demonstration:
https://youtu.be/2bSna_iPMSU
When you import a JPG image (any image) into CorelDRAW, it is no longer a JPG but instead just an uncompressed image with a given number of pixels.The JPG compression that was in the original file is no longer present but the deterioration caused by this compression is now part of the image.When you export as a JPG, DRAW compresses the image again based on your export settings, and the new JPG may be bigger or smaller than the original and it may also look more or less "destroyed" compared to the original image.JPG uses a lossy compression algorithm that will impair the image each time it is opened and saved.
I think I understand.
But, it makes me very confused, Ronny.
Because when you export an image, it is not clear how much you are adding or subtracting quality from the original image.
I set the quality of the exported image, until it is equivalent to the size(in Bytes) of the imported image(the original).
Because keeping the size equivalent (in bytes) of the exported and imported image (the original), is what I understand as a reference of how much Corel is adding or reducing quality in relation to the original image.
In my head it works like this, kkk.
A practical example:
I set the quality of the exported image to 65%, and the size(in Bytes) became equivalent to the size(in Bytes) of the original image.
So I conclude that if you set the exported image quality higher than 65%, you would in fact be applying quality, because from then on, the size of the exported image starts to be bigger (in bytes) than the original.
And if you set the exported image quality lower than 65%, you will not be applying any quality at all, only reducing it, because the exported image starts to become smaller (in bytes) than the original.
Is my reasoning correct?
Another thing, I performed quality tests.
The exported image with 100% quality seems to be even worse.
When exporting, I reduced the quality to 65% and it looked better.
observation:I made the image into a video for youtube, because the forum does not accept my links, and the image is too small here
Reducing the quality, was supposed to get worse right ?Head explodes!
Sepulnation |m| said:So I conclude that if you set the exported image quality higher than 65%, you would in fact be applying quality, because from then on, the size of the exported image starts to be bigger (in bytes) than the original.
No. I understand how you are thinking but that's not how it works.Let's say you have a perfect original image.When you save it is a JPG the first time (from any program), the JPG filter uses lossy compression that will change and destroy the image to some degree, more or less depending on how much it is compressed.If you open and save as JPG repeatedly, every save will add more artifacts and these changes can not be undone *.When you import an image into Draw, it will be just an uncompressed image in Draw and not specifically a JPG, TIF or PNG (for example) any more.This means that all deterioration caused by previous lossy compression will be part of that image and no matter what you do, this new image will always be the best you have *.The image inside the Draw file will not change in any way even if you save repeatedly though, because Draw uses lossless compression that will keep all information.If you decide to export from Draw using the JPG filter however, the JPG will be a little bit deteriorated even if you try to save to a file size equal to the original, because you are compressing an image that has all the flaws from previous compression built in.You can never get a JPG that is better than what you have in Draw, even if you set the quality to 100%.Not sure if there is any compression at 100% but every percentage below that will destroy the image a little and add more flaws.FWIW, I usually use 80 - 90% quality setting when I export to JPG.It gives a decent quality and reduces the file size quite a lot.* There are filters that can reduce compression artifacts, but you can not regain any of the already lost information, only blur out the defects a little.
Here's an image comparing JPG export with 90% versus 10% quality.You can see some JPG artifacts already at 90% and they are grotesque at 10%.