Cover Art & filesize

[DetlevD]

@Bryan B

... I just tried MP3Tag to add art to an album and here's my problem: It blows up the size of the jpg. I'm kind of picky about the art. I like 500x500, but I keep the filesize small by going for a higher jpeg compression. In my test run, I used a file that was 25K. When I paste it into the MP3tag editor, it tells me the filesize is 146k. When I save the files, they are 150k larger. When I did the same with MusicMatch, the files would be (about) 25k larger.
Why does MP3tag enlarge the size of the jpeg, and is there anything I can do about it? ...

Mp3tag supports two methods for embedding cover art into the tag data area of a media file:

1. by embedding the physical image file directly from the disk;
2. by Windows Clipboard.

In case 1 the image file will be embedded "as is".
That means, an embedded image file with filesize of 25 KB enlarges the filesize of the media file by about 25 KB.

In case 2 the image file will be transported via the Windows Clipboard.
That means, at first a JPG compressed image file will be decompressed into a "Device-Independent Bitmap" (DIB), for example, a 500x500 24bit image's data size grows from compressed 25 KB to uncompressed 732 KB.

Afterwards when embedding from the Windows Clipboard into the media file, the bitmap image data will be compressed into the given JPG compressed format.
However, the initial compression factor get lost.

See attached zip file having a test file containing two identical pictures:
one embedded by Windows Clipboard, the other embedded directly as file from the disk.
20140815.Mp3tag.Test.EmbeddedCover.zip (138 KB)

See also ....
http://msdn.microsoft.com/en-us/library/dd...2(v=vs.85).aspx

DD.20140815.1003.CEST

20140815.Mp3tag.Test.EmbeddedCover.zip (138 KB)