package be.nikiroo.utils; import java.io.File; import java.io.IOException; import java.io.InputStream; import be.nikiroo.utils.serial.SerialUtils; /** * This class offer some utilities based around images. * * @author niki */ public abstract class ImageUtils { private static ImageUtils instance = newObject(); /** * Get a (unique) instance of an {@link ImageUtils} compatible with your * system. * * @return an {@link ImageUtils} */ public static ImageUtils getInstance() { return instance; } /** * Save the given resource as an image on disk using the given image format * for content, or with "png" format if it fails. * * @param img * the resource * @param target * the target file * @param format * the file format ("png", "jpeg", "bmp"...) * * @throws IOException * in case of I/O error */ public abstract void saveAsImage(Image img, File target, String format) throws IOException; /** * Return the EXIF transformation flag of this image if any. * *

* Note: this code has been found on internet; thank you anonymous coder. *

* * @param in * the data {@link InputStream} * * @return the transformation flag if any * * @throws IOException * in case of IO error */ protected static int getExifTransorm(InputStream in) throws IOException { int[] exif_data = new int[100]; int set_flag = 0; int is_motorola = 0; /* Read File head, check for JPEG SOI + Exif APP1 */ for (int i = 0; i < 4; i++) exif_data[i] = in.read(); if (exif_data[0] != 0xFF || exif_data[1] != 0xD8 || exif_data[2] != 0xFF || exif_data[3] != 0xE1) return -2; /* Get the marker parameter length count */ int length = (in.read() << 8 | in.read()); /* Length includes itself, so must be at least 2 */ /* Following Exif data length must be at least 6 */ if (length < 8) return -1; length -= 8; /* Read Exif head, check for "Exif" */ for (int i = 0; i < 6; i++) exif_data[i] = in.read(); if (exif_data[0] != 0x45 || exif_data[1] != 0x78 || exif_data[2] != 0x69 || exif_data[3] != 0x66 || exif_data[4] != 0 || exif_data[5] != 0) return -1; /* Read Exif body */ length = length > exif_data.length ? exif_data.length : length; for (int i = 0; i < length; i++) exif_data[i] = in.read(); if (length < 12) return -1; /* Length of an IFD entry */ /* Discover byte order */ if (exif_data[0] == 0x49 && exif_data[1] == 0x49) is_motorola = 0; else if (exif_data[0] == 0x4D && exif_data[1] == 0x4D) is_motorola = 1; else return -1; /* Check Tag Mark */ if (is_motorola == 1) { if (exif_data[2] != 0) return -1; if (exif_data[3] != 0x2A) return -1; } else { if (exif_data[3] != 0) return -1; if (exif_data[2] != 0x2A) return -1; } /* Get first IFD offset (offset to IFD0) */ int offset; if (is_motorola == 1) { if (exif_data[4] != 0) return -1; if (exif_data[5] != 0) return -1; offset = exif_data[6]; offset <<= 8; offset += exif_data[7]; } else { if (exif_data[7] != 0) return -1; if (exif_data[6] != 0) return -1; offset = exif_data[5]; offset <<= 8; offset += exif_data[4]; } if (offset > length - 2) return -1; /* check end of data segment */ /* Get the number of directory entries contained in this IFD */ int number_of_tags; if (is_motorola == 1) { number_of_tags = exif_data[offset]; number_of_tags <<= 8; number_of_tags += exif_data[offset + 1]; } else { number_of_tags = exif_data[offset + 1]; number_of_tags <<= 8; number_of_tags += exif_data[offset]; } if (number_of_tags == 0) return -1; offset += 2; /* Search for Orientation Tag in IFD0 */ for (;;) { if (offset > length - 12) return -1; /* check end of data segment */ /* Get Tag number */ int tagnum; if (is_motorola == 1) { tagnum = exif_data[offset]; tagnum <<= 8; tagnum += exif_data[offset + 1]; } else { tagnum = exif_data[offset + 1]; tagnum <<= 8; tagnum += exif_data[offset]; } if (tagnum == 0x0112) break; /* found Orientation Tag */ if (--number_of_tags == 0) return -1; offset += 12; } /* Get the Orientation value */ if (is_motorola == 1) { if (exif_data[offset + 8] != 0) return -1; set_flag = exif_data[offset + 9]; } else { if (exif_data[offset + 9] != 0) return -1; set_flag = exif_data[offset + 8]; } if (set_flag > 8) return -1; return set_flag; } /** * Check that the class can operate (for instance, that all the required * libraries or frameworks are present). * * @return TRUE if it works */ abstract protected boolean check(); /** * Create a new {@link ImageUtils}. * * @return the {@link ImageUtils} */ private static ImageUtils newObject() { for (String clazz : new String[] { "be.nikiroo.utils.ui.ImageUtilsAwt", "be.nikiroo.utils.android.ImageUtilsAndroid" }) { try { ImageUtils obj = (ImageUtils) SerialUtils.createObject(clazz); if (obj.check()) { return obj; } } catch (Throwable e) { } } return null; } }