China DOS Union

Brother M's research is quite thorough.

On this basis, I am willing to share my views with everyone.

First of all, what cannot be ignored is that this file is a GIF file.

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GIF is a compression method based on mathematical formulas.
Its principle is to describe discrete values with continuous functions.

Then, after compression, the file will have a loss of image quality. These losses must be reduced to the range that can be observed by the naked eye (according to the compression ratio) or to an acceptable range.

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For us, these files will have a loss of image quality after compression. In GIF, the image loss means the smearing of pixels, that is, blurring, but these only consider the positive display effect, so the situation where there is an approximate white instead of white on the image, and a similar black but actually another color. These are because when displaying positively, due to being extremely similar to the adjacent colors, the human eye cannot detect it (the compression ratio is appropriate). But when inverting the color, it completely distinguishes from the foreground color, background color, and transparent color, so there are "hidden" images.

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In fact, such a phenomenon completely exists in other complex images. For example, the two emoticons at the end of this article will have "white" edges when inverting the color, but since we are sure to ignore the noise after inverting the color of complex images. So when such a situation occurs in simple images - especially regular geometric figures (the color smearing generated by the compression algorithm is also regular) - we are very surprised.

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Forgive me for writing the above words in paragraphs, because my old K6-2 computer may be approaching the end of its life, and it frequently freezes

[ Last edited by fdsiuha on 2005-9-5 at 23:20 ]

Just now I found that IE still fills with blue at intervals when inverting the colors of 16-bit JPG images, at least my eyes tell me so.
In addition, I found that there are still various colors in the inverted image, at least there are pixels of various colors.

Re Michael (Post 17):

>>Just now I found that IE still fills blue in intervals for 16-bit JPG images when inverting colors.

That means that the JPEG format also has a similar "dithering" effect. Maybe BitMap also does, which might be related to the image editing software.

>>I found that the inverted color image still has various colors, at least there are pixels of various colors.

Then it means that there are still many inverted colors, very likely just as many. It's just that the originally similar colors are very different after inversion, and the originally very different colors are反而 close after inversion. For example, the black of your ID and the red of the level.

[ Last edited by willsort on 2005-9-6 at 19:12 ]

However, everyone can consider that GIF files can be saved as Transparent type. Does the full blue filling have anything to do with this?

No

Member levels are displayed in bold font. At this time, no matter what color it is, it is all inverted to the system background color.

For the specific explanation of the image problem, please see my reply above.

The pixels displayed after inversion are not caused by IE and software, because they are neither background color nor foreground color, but extra pixels caused by compression. Because of them, the quality of the image will deteriorate.

[ Last edited by fdsiuha on 2005-9-5 at 23:17 ]

Re All:

This is 3 pictures I made with "Paint", you can compare them.


GIF JPG PNG

[ Last edited by willsort on 2005-9-6 at 19:18 ]

TO willsort:
I would like to ask: How do you capture the images?
Because, generally, when you click elsewhere, that effect will disappear?
...
??

Re GOTOmsdos:

I used the region capture function of wincam2 (408K, probably a simplified version), and later I switched to the region capture function of SPX Capture, neither of which encountered the problem you mentioned.

Is the printscreen not working?

Re fdsiuha:

PrintScreen works, but after copying, you need to crop it yourself and save it as a GIF, which is too troublesome, so I switched to using ready-made software.

No, mine is normal.

After inverting the colors of the three different formats of the cross of willsort, when viewed with a magnifying glass, they are all the same.

Re JonePeng:

Upon careful inspection, JPG images will have some "noise," while GIF and PNG do not; all three images were generated using "Paint," so the differences are likely related to the compression algorithms of the image formats.

That is to say, the "blurring of pixels" mentioned by brother fdsiuha also exists in other image formats, and I have not yet determined whether it is described by a continuous function. Other formats such as Bmp and TIF cannot be embedded in web pages, so their IE inverse color effects cannot be observed.

GIF and PNG are lossless compression, but when using software to draw, if the source image is in other lossy compression formats, and finally saved as GIF or PNG, the situation above will occur. This kind of thing happens frequently.

The computer often freezes. The previous post took 7 or 8 times to finish writing. The logic is a bit chaotic

[ Last edited by fdsiuha on 2005-9-11 at 21:58 ]

Re fdsiuha:

Add one more point: All three images are made from BMP source images.