Java uses Thumbnailator-0.4.8.jar to generate thumbnails

Scene One: Image size unchanged, modify picture file type

use:

thumbnails.of ("F:\\image\\img_20131229_114806.png") . Scale (1f)

. OutputFormat ("jpg")

. ToFile ("f:\\image\\output\\img_20131229_114806");

Note:OutputFormat: The picture format of the output. Note that the ToFile () method does not have a suffix for the file type after the method is used, otherwise a picture of IMG_20131229_114806.jpg.jpg is generated.

Scene Two: Image size unchanged, compressed picture file size

Use:

thumbnails.of ("F:\\image\\img_20131229_114806.png") . Scale (1f)

. Outputquality (0. 25f)

. OutputFormat ("jpg")

. ToFile ("f:\\image\\output\\img_20131229_114806");

Note: outputquality: Output picture quality, Range: 0.0~1.0,1 for highest quality. Note the image format that you output when you use this method must be a JPG (that is, OutputFormat ("JPG"). Other formats I have not tried, interested in themselves can try). Otherwise if the output PNG format picture, then this method effect invalid "This actually should be considered a bug".

Scene Three: Compress to the specified picture size (for example: Horizontal 400 high 300), do not maintain the picture scale

Use:

thumbnails.of ("F:\\image\\img_20131229_114806.png")

. forcesize (+)

. ToFile ("f:\\image\\output\\img_20131229_114806");

Scene Four: Compress to the specified picture size ( For example: Horizontal 400 high), keep the picture intact, the extra part cut off

Use:

String ImagePath = "F:\\image\\img_20131229_114806.jpg";

BufferedImage image = Imageio.read (new File (ImagePath));

builder<bufferedimage> Builder = null;   

int imagewidth = Image.getwidth ();

int imageheitht = Image.getheight ();

if (float) + /- (float) imagewidth/imageheitht) {

if (ImageWidth > Imageheitht) {

image = Thumbnails.of (imagePath). Height (+). Asbufferedimage ();

} Else {

image = Thumbnails.of (imagePath). Width (N). Asbufferedimage ();

}

Builder = thumbnails.of (image). Sourceregion (Positions.center, .) . Size ( );

} Else {

builder = thumbnails.of (image). Size ( +);

}

Builder.outputformat ("jpg"). ToFile ("f:\\image\\output\\img_20131229_114806");

This is a bit more complicated than the size () method (since the height ratio is not necessarily 4/3, so the compressed picture is either a zero or a high of 300) and cannot be used with the Forcesize () method. First judge the cross-height ratio, determine whether the horizontal 400 compression or high 300 compression, after compression by the center of the 400*300 area to cut, so that the resulting picture is 400*300 cropped thumbnail.

when using the size () or Forcesize () method, if the picture is smaller than the specified size (such as size (400, 300) and the picture is 40*30), it is stretched to the specified size.  

Java uses Thumbnailator-0.4.8.jar to generate thumbnails