How can I merge two TIFF images in one...?

Question

I need some help please, I am looking for a way to "resize" black & white single TIFF images.
The process I need to do is like cutting a small image and paste it over a new blank letter-size image (at 300 dpi), like a template.
Or better yet, is there a way to do something like this...?
Open image...
image.*width* = 2550;
image.*height* = 3300;
image.save();Some APIs and topics in the internet do or talk about resizing, but the final images get stretched or shrinked and I need them not to do so at all.
Also, I do not need to display the images, only to get the TIFF images processed and saved back to a file.
How can I do this with Java and JAI? Unfortunately I am almost new to this and I don't know how difficult it might be to deal with images.

Answer 1

If 2550 x 3300 isn't the original aspect ratio of the image, then the image is going to looked streched or shrinked in at least one dimension. There is no way around that. It would be like resizing a 2 pixel by 2 pixel image into a 3 pixel by 6 pixel image. The image would look like it's height shrunk or it's width stretched. Had I resized it to 3 pixels by 3 pixels or 6 pixels by 6 pixels, though, then it wouldn't look shrunken or streched.
Open image...
image.*width* = 2550;
image.*height* = 3300;
image.save();*1)* To open a TIFF image you can use the javax.swing.ImageIO class. It has these static methods
read(File input)
read(ImageInputStream stream)
read(InputStream input)
read(URL input) You can use which ever method you want. But first you need to install [JAI-ImageIO|https://jai-imageio.dev.java.net/binary-builds.html]. The default ImageReaders that plug themselves into the ImageIO package are BMP, PNG, GIF, and JPEG. JAI-ImageIO will add TIFF, and a few other formats.
The downside is that if clients want to you use your program on their machine then they to will need to install JAI-ImageIO to read the tiffs. To get around this, you can go to your Java/jdk1.x.x_xx/jre/lib/ext/ folder and copy the jai_imageio.jar file (after you've installed JAI-ImageIO). You can also obtain this jar from any one of the zip files of the [daily builds|https://jai-imageio.dev.java.net/binary-builds.html#Daily_builds]. If you add this jar to your program's classpath and package it together with your program, then clients won't need to install JAI-ImageIO and you'll still be able to read TIFF's. The downside of simply adding the jar to the classpath is that you won't be able to take advantage of a natively accelerated JPEG reader that comes with installing JAI-ImageIO (instead, ImageIO will use the default one).
*2)* Once you've installed [JAI-ImageIO|https://jai-imageio.dev.java.net/binary-builds.html] and used ImageIO.read(...), you'll have a BufferedImage. To resize it you can do the following
BufferedImage newImage = new BufferedImage(2550,3300,BufferedImage.TYPE_BYTE_BINARY);
Graphics2D g = newImage.createGraphics();
g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g.drawImage(oldImage,0,0,2550,3300,null);
g.dispose();Here, I simply drew the old image (the one returned by ImageIO.read(...)) onto a new BufferedImage object of the appropriate size. Because you said they were black and white TIFF's, I used BufferedImage.TYPE_BYTE_BINARY, which is a black and white image. If you decide to use one the BufferedImage types that support color, then a 2550x3330 image would require at least 25 megabytes to hold into memory. On the other hand, a binary image of that size will only take up about one meg.
I specified on the graphics object that I wanted Bilinear Interpolation when scaling. The default is Nearest Neighbor interpolation, which while fast, dosen't look very good. Bilinear offers pretty good results scaling both up or down at fast speeds. Bicubic interpolation is the next step up. If you find the resized image to be subpar, then come back and post. There are a couple of other ways to resize an image.
Note, however, if 2550 x 3300 is not the same aspect ratio as the the TIFF image you loaded, then the resized image will look shrunk or stretched along one dimension. There is absolutely no way around this no matter what resizing technique you use. You'll need an image whose original dimensions are in a 2550/3300 = .772 ratio if you want the resized image to not look like it's streched (you can crop the opened image if you want).
*3)* Now we save the "newImage" with the same class we read images with: ImageIO . It has these static methods
write(RenderedImage im, String formatName, File output)
write(RenderedImage im, String formatName, ImageOutputStream output)
write(RenderedImage im, String formatName, OutputStream output)You'll suply the resized BufferedImage as the first parameter, "tiff" as the second parameter and an appropriate output for the third parameter. It's pretty much a one line statement to read or write an image. All in all, the whole thing is about 7 lines of code. Not bad of all.
Now as for the 300 dpi thing, there is a way to set the dpi in the Image's metadata. I'm pretty good at reading an image's metadata, but I've never really tried writing out my own metadata. I know you can set the dpi, and I have a somewhat vague idea how it might be done, but it's not something I've tried before. I think I'll look more into it.