File talk:Moon phases 00.jpg

Use Moon_phases_00.png to make your derivative work

Why not just mark a 256 KB JPEG as superseded by a 183 KB PNG? Incnis Mrsi (talk) 20:16, 30 August 2011 (UTC)

Actually you're right. I didn't notice that. As I compare the two versions, the PNG has more perfect lines and edges, of course, but JPG seems rendered better. But it's all right to delete one of them, I think. - Orion 8 (talk) 02:07, 31 August 2011 (UTC)

Now I see why the size difference appeared. You changed the PNG version to a worse one. I don't agree, the original image has fine color shades, but now seems roughly, steps in the transition. There was nothing wrong in my version, I don't know why you found to have to change. And now the two versions require more storage place the the one did. I will make an attempt to undo your simplifying. - Orion 8 (talk) 02:20, 31 August 2011 (UTC)

Of course, there was nothing wrong there. But I think that JPEG makes heavier distortion to this kind of images than color reduction to indexed. Maybe I misbelieve, though. Incnis Mrsi (talk) 11:14, 31 August 2011 (UTC)

Well, the color reduction always makes heavy distortion in images which contain fine color transition areas. Like the sky in the new moon phases. You see, I spotted the imperfection at the first moment, I just could not understand why the JPG is better than the PNG. I created this illustration with the greatest attention, I like the result, and I was musing about this mistake. But I was already very sleepy, that's why I did not notice the problem at first. This would have been my first thing to do when I wake up. So, please let me undo the reduced version, I have shared the original PNG just to have an intact copy for anybody who wants to make a derived version with other texts in another language. The storage place is not a pushing factor in Wikipedia, and, you see, now we have lost space when storing a second image beside the first one. Most editors don't come at this aspect, misled by the instruction "upload a new version", I'm sure of it.

I wonder how you noticed the color depth of an image in the Commons in an illustration which does not show other problems. I think you lost valuable power when you was troubling with this unimportant thing. Go ahead, there are still a plenty of missing illustrations we have to create for the articles, that will be much more useful work for the community. Привет! - Orion 8 (talk) 13:50, 31 August 2011 (UTC)

Should I undo my change of Moon_phases_00.png, and upload it under different name? And is the 255 color version better than this JPEG? Incnis Mrsi (talk) 19:29, 4 September 2011 (UTC)

I don't feel that the reduced color version looks better than the JPG, just because the JPG compression creates new colors for some pixels to make the sense of the substituted pixels, while keeping the pixels in more compressable values. While doing this the JPG compressing programs spread, blur the boundaries of the new, regulated color stripes if some are created, for keeping the view same soft and natural, as much as it is possible.

The original PNG image has 51514 different colors. The JPG file which was created from this, contains 62270 unique colors. And this file is much smaller. So not the reducing the color numbers are the only way to make an image smaller but more the compression method, you can see. Tthe JPG compression algorithm is a very refined and clever one.

If you take away a huge number of colors from an image which has fine color shadings – and my PNG image has –, than you crate rough color steps on these shading areas. With your reducing you forced to use 200 times (!) less colors, and after that you used a compression method which is just invented for images without shaded colors, to keep exactly the same colors, for images having big spots of the same colors and sharp boundaries. Like diagrams or lined sketches, or texts. And with this compression you create the well known "rings" on the shaded surfaces. Just as in my views for the bright sky, which is made to suggest the view of the sky very close – but not the same distance – to the Sun.

Incidentally: using strong JPG compression for sketches, that is a common mistake, which creates garbage pixels, shades beside the lines, and changes the colors visibly. On the other hand, reducing the colours of a photo makes that very rough, looks a graphics made from a photo.

At this case I watched the result very carefully, because this is my best and nicest image here, and I would like it the same nice as it was. That's why I would like to keep the quality of this image. You know already, we have already lost storage, not gained whith the replacing, so there is no reason to replace an image with a worse one. But if you find it necessary, you are free to make a derivative of any image of the Commons, also this one.

But now I am thinking about deleting completely the PNG file. It seems not very important to keep, because the JPG version seems well enough. With deleting the file we would really gain storage space, even if this is not an important thing. So maybe we could close this problem with deletion, по моему мнению. Shall we go? :) - Orion 8 (talk) 16:27, 5 September 2011 (UTC)