A funny Java example to create an ASCII art graphic. The concept is simple, get the image’s rgb color in “integer mode”, later, replace the color’s integer with ascii text. P.S This example is credited for this post ASCIIArtService.java package com.mkyong.service; import java.awt.*; import java.awt.image.BufferedImage; import java.io.IOException; public class ASCIIArtService { public static void main(String[] […]
This article shows how to convert an PNG image format to an JPEG image format in Java. 1. PNG Image Below is a PNG image with a transparent background. 2. Java Convert PNG to JPEG Since the JPEG image format doesn’t support the transparent background, we will create a white background as a replacement. Below […]
In Android, you can use “android.widget.ImageView” class to display an image file. Image file is easy to use but hard to master, because of the various screen and dpi in Android devices. Note Please refer to this official Android’s “Drawable Resource” and “Screen Support” article for better understand of how image works in Android. In […]
In JAX-RS, for user to download an image file, annotate the method with @Produces(“image/image-type”) : Put @Produces(“image/png”) on service method, for “png” image. Set “Content-Disposition” in Response header to prompt a download box. Note For other image types, refer to this list of the image types 1. Download Image in JAX-RS Full example to download […]
In this tutorial, we show you how to save an image file into MongoDB, via GridFS API. The GridFS APIs are able to serve other binary files as well, like video and music files. Note For detail explanation, read this MongoDB GridFS manual. 1. Save image Code snippets to save an image file into MongoDB, […]
In JSF, you can use <h:graphicImage /> tag to render a HTML “img” element. For example, an image named “sofa.png” in a resources folder, see figure below : 1. JSF 1.x graphicImage In JSF 1.x you can hard-coded above image URL directly in the “value” attribute : JSF… <h:graphicImage value="resources/images/sofa.png" /> HTML output… <img src="resources/images/sofa.png;" […]
To check if an image is loaded successful or not, you can combine the use of jQuery ‘load()‘ and ‘error()‘ event : $(‘#image1’) .load(function(){ $(‘#result1’).text(‘Image is loaded!’); }) .error(function(){ $(‘#result1’).text(‘Image is not loaded!’); }); If the image is loaded successful, the load() function is called, otherwise the error() function is called. Try it yourself <html> […]
To save an image into database, you need to define a table column as blob data type in MySQL, or equivalent binary type in others database. In Hibernate side, you can declare a byte array variable to store the image data. Download this example – Hibernate-Image-Example.zip Here’s an Maven project to use Hibernate to save […]
The “javax.imageio” package is used to deal with the Java image stuff. Here’s two “ImageIO” code snippet to read an image file. 1. Read from local file File sourceimage = new File("c:\\mypic.jpg"); Image image = ImageIO.read(sourceimage); 2. Read from URL URL url = new URL("https://mkyong.com/image/mypic.jpg"); Image image = ImageIO.read(url); ImageIO Example In this example, you […]
In Java, we can use the javax.imageio.ImageIO class to read and write an image. 1. Read an image Read an image from a file. BufferedImage image = ImageIO.read(new File("c:\\test\\image.png")); Read an image from an URL. BufferedImage image = ImageIO.read(new URL("https://example.com/image.png")); 2. Write or save an image Write or save an image in different image formats. […]
Image File Extension Regular Expression Pattern ([^\s]+(\.(?i)(jpg|png|gif|bmp))$) Description ( #Start of the group #1 [^\s]+ # must contains one or more anything (except white space) ( # start of the group #2 \. # follow by a dot "." (?i) # ignore the case sensive checking for the following characters ( # start of the […]
This article shows two ways to resize an image (create a thumbnail) in Java. 1. Original Image, 544×184 Below is a Google logo image, width, height 544×184, and file size 14k. Later, we will resize the below image to a new width and height 300×150. 2. Resize an image or create a thumbnail. This Java […]
This article shows how to convert a byte[] to a BufferedImage in Java. InputStream is = new ByteArrayInputStream(bytes); BufferedImage bi = ImageIO.read(is); The idea is puts the byte[] into an ByteArrayInputStream object, and we can use ImageIO.read to convert it to a BufferedImage. 1. Convert byte[] to BufferedImage. The below example shows how to convert […]
This article shows how to convert a BufferedImage to a byte array or byte[]. BufferedImage bi = ImageIO.read(new File("c:\\image\\mypic.jpg")); ByteArrayOutputStream baos = new ByteArrayOutputStream(); ImageIO.write(bi, "jpg", baos); byte[] bytes = baos.toByteArray(); The idea is uses the ImageIO.write to write the BufferedImage object into a ByteArrayOutputStream object, and we can get the byte[] from the ByteArrayOutputStream. […]
Often times, we need to “preload” an image into browser’s cache for performance concern. For instance, we have a mouseover event and the image needs to be update without any delay. This “Preloading” stuff can be achieved in two ways , either JavaScript or HTML code. Javascript We can “preload” an image with the following […]
