In addition to %0A which you can use for making multiline text images, you can also use underlining and strikethrough.
For underlining use %0D and _, for example:
/image.php?text=Underline.%0D________
For strikethrough use %0D and %E2%80%93, for example:
/image.php?text=Strikethrough.%0D%E2%80%93%E2%80%93%E2%80%93%E2%80%93
%E2%80%93%E2%80%93%E2%80%93%E2%80%93%E2%80%93%E2%80%93
If you want to use both of them in one line you will have to use %20 to dispose the next block of modifying symbols:
/image.php?text=Underline%20and%20Strikethrough.%0D_______%20%20%20%20
%20%20%20%20%20%E2%80%93%E2%80%93%E2%80%93%E2%80%93%E2%80%93%E2%80%93
%E2%80%93%E2%80%93%E2%80%93%E2%80%93
As you see all modifying symbols for whole line are put after %0D in one string after the whole modifyable text and not after each modifyable word. This makes easy to put on and take off modifying string for whole line when it`s necessary.
If the text is on several lines, each line has its own disposition of modifying symbols:
/image.php?text=Underline%20and%0D_______%0AStrikethrough.%0D%E2%80%93
%E2%80%93%E2%80%93%E2%80%93%E2%80%93%E2%80%93%E2%80%93%E2%80%93
%E2%80%93%E2%80%93
Theese are only some examples how to use symbol combining. Using %0D and other symbols from Windows Charmap you can easy make images of characters which even doesn`t exist in any font.
LV. Image 图像函数
简介
PHP 不仅限于只产生 HTML 的输出。还可以创建及操作多种不同图像格式的图像文件，包括 gif，png，jpg，wbmp 和 xpm。更方便的是，PHP 可以直接将图像流输出到浏览器。要处理图像，需要在编译 PHP 时加上图像函数的 GD 库。GD 和 PHP 还可能需要其它的库，视乎需要支持哪些图像格式而定。
可以在 PHP 中使用图像函数来得到 JPEG，GIF，PNG，SWF，TIFF 和 JPEG2000 图像的大小。
注: 阅读需求一节以了解怎样扩展图像能力来读取，写入和修改图像以及读取数码相机拍摄的照片中的元数据。
需求
如果有 GD 库（在 http://www.boutell.com/gd/），可以创建及操作图像。
所能处理的图像格式取决于所安装的 GD 版本，以及其它 GD 可能用到的来访问这些图像格式的库。低于 gd-1.6 版本的 GD 支持 GIF 图像格式，不支持 PNG，高于 gd-1.6 低于 gd-2.0.28 的版本支持 PNG，不支持 GIF。在 gd-2.0.28 中又重新支持 GIF 了。
注: 自 PHP 4.3 起绑定了一个 GD 库的版本。这个绑定的版本具有一些附加的特色例如透明混色，应优先使用此版本，因为它的代码维护得更好以及更加稳定。
可能想要增加 GD 处理的图像格式。
表格 1. 所支持的图像格式
| 图像格式 | 要下载的库 | 注解 |
|---|---|---|
| gif | 仅在低于 gd-1.6 与高于 gd-2.0.28 的 GD 版本中支持。PHP 4.3.0 以及绑定的 GD 库中支持只读的 GIF。PHP 4.3.9 和 PHP 5.0.1 起支持写入。 | |
| jpeg-6b | ftp://ftp.uu.net/graphics/jpeg/ | |
| png | http://www.libpng.org/pub/png/libpng.html | 仅在高于 gd-1.6 的 GD 版本中支持。 |
| xpm | ftp://metalab.unc.edu/pub/Linux/libs/X/!INDEX.html | 如果系统中安装了 X 环境，则很可能已经有了这个库。 |
可能想要增强 GD 处理不同字体的能力。支持下列字库：
表格 2. 所支持的字库
| 字库 | 下载位置 | 注解 |
|---|---|---|
| FreeType 1.x | http://www.freetype.org/ | |
| FreeType 2 | http://www.freetype.org/ | |
| T1lib | ftp://sunsite.unc.edu/pub/Linux/libs/graphics/) | 支持 Type 1 字体。 |
如果 PHP 编译时指定了 --enable-exif，就可以操作存储于 JPEG 和 TIFF 图像文件头中的信息。这样就可以读取上面提到的数码相机生成的照片中的元数据。这些函数不需要 GD 库。
安装
要激活 GD 支持，配置 PHP 时加上 --with-gd[=DIR]，DIR 是 GD 的基本安装目录。要使用推荐的绑定的 GD 库版本（首次绑定于 PHP 4.3.0），使用 --with-gd。要编译 GD 库，需要libpng 和 libjpeg。
在 Windows 中，需要将 GD2 的 DLL 文件 php_gd2.dll 作为一个扩展包含在 php.ini 中。GD1 的 DLL 文件 php_gd.dll 在 PHP 4.3.2 中被删除了。此外要注意首选的真彩色图像函数，例如 imagecreatetruecolor()，需要 GD2。
注: 要在 Windows 下启用 exif，在 php.ini 中 php_mbstring.dll 必须在 php_exif.dll 之前加载。
要在 PHP 3 中禁止 GD 支持，在配置时加上 --without-gd。
要增强 GD 的能力以处理更多的图像格式，在配置 PHP 时指定 --with-XXXX 的配置开关。
表格 3. 所支持的图像格式
| 图像格式 | 配置开关 |
|---|---|
| jpeg-6b | 要激活 jpeg-6b 的支持，加上 --with-jpeg-dir=DIR. |
| png | 要激活 png 的支持，加上 --with-png-dir=DIR。注意，libpng 需要 zlib library，因此配置中还要加上 --with-zlib-dir[=DIR]。 |
| xpm | 要激活 xpm 的支持，加上 --with-xpm-dir=DIR。如果配置时提示找不到所需要的库，可以加上到 X11 库的路径。 |
注: 当把 PHP 和 libpng 一起编译时，必须使用和 GD 库连接的同一个版本。
要增强 GD 的能力以处理更多的字体，在配置 PHP 时指定 --with-XXXX 的配置开关。
资源类型
本扩展模块未定义任何资源类型。
预定义常量
以下常量由本扩展模块定义，因此只有在本扩展模块被编译到 PHP 中，或者在运行时被动态加载后才有效。
- IMG_GIF (integer)
- IMG_JPG (integer)
- IMG_JPEG (integer)
- IMG_PNG (integer)
- IMG_WBMP (integer)
- IMG_XPM (integer)
- IMG_COLOR_TILED (integer)
- IMG_COLOR_STYLED (integer)
- IMG_COLOR_BRUSHED (integer)
- IMG_COLOR_STYLEDBRUSHED (integer)
- IMG_COLOR_TRANSPARENT (integer)
- IMG_ARC_ROUNDED (integer)
- IMG_ARC_PIE (integer)
- IMG_ARC_CHORD (integer)
- IMG_ARC_NOFILL (integer)
- IMG_ARC_EDGED (integer)
- IMAGETYPE_GIF (integer)
- IMAGETYPE_JPEG (integer)
- IMAGETYPE_PNG (integer)
- IMAGETYPE_SWF (integer)
- IMAGETYPE_PSD (integer)
- IMAGETYPE_BMP (integer)
- IMAGETYPE_WBMP (integer)
- IMAGETYPE_XBM (integer)
- IMAGETYPE_TIFF_II (integer)
- IMAGETYPE_TIFF_MM (integer)
- IMAGETYPE_IFF (integer)
- IMAGETYPE_JB2 (integer)
- IMAGETYPE_JPC (integer)
- IMAGETYPE_JP2 (integer)
- IMAGETYPE_JPX (integer)
- IMAGETYPE_SWC (integer)
范例
- 目录
- gd_info -- 取得当前安装的 GD 库的信息
- getimagesize -- 取得图像大小
- image_type_to_extension -- 取得图像类型的文件后缀
- image_type_to_mime_type -- 取得 getimagesize，exif_read_data，exif_thumbnail，exif_imagetype 所返回的图像类型的 MIME 类型
- image2wbmp -- 以 WBMP 格式将图像输出到浏览器或文件
- imagealphablending -- 设定图像的混色模式
- imageantialias -- 是否使用抗锯齿（antialias）功能
- imagearc -- 画椭圆弧
- imagechar -- 水平地画一个字符
- imagecharup -- 垂直地画一个字符
- imagecolorallocate -- 为一幅图像分配颜色
- imagecolorallocatealpha -- 为一幅图像分配颜色 + alpha
- imagecolorat -- 取得某像素的颜色索引值
- imagecolorclosest -- 取得与指定的颜色最接近的颜色的索引值
- imagecolorclosestalpha -- 取得与指定的颜色加透明度最接近的颜色
- imagecolorclosesthwb -- 取得与给定颜色最接近的色度的黑白色的索引
- imagecolordeallocate -- 取消图像颜色的分配
- imagecolorexact -- 取得指定颜色的索引值
- imagecolorexactalpha -- 取得指定的颜色加透明度的索引值
- imagecolormatch -- 使一个图像中调色板版本的颜色与真彩色版本更能匹配
- imagecolorresolve -- 取得指定颜色的索引值或有可能得到的最接近的替代值
- imagecolorresolvealpha -- 取得指定颜色 + alpha 的索引值或有可能得到的最接近的替代值
- imagecolorset -- 给指定调色板索引设定颜色
- imagecolorsforindex -- 取得某索引的颜色
- imagecolorstotal -- 取得一幅图像的调色板中颜色的数目
- imagecolortransparent -- 将某个颜色定义为透明色
- imageconvolution -- 用系数 div 和 offset 申请一个 3x3 的卷积矩阵
- imagecopy -- 拷贝图像的一部分
- imagecopymerge -- 拷贝并合并图像的一部分
- imagecopymergegray -- 用灰度拷贝并合并图像的一部分
- imagecopyresampled -- 重采样拷贝部分图像并调整大小
- imagecopyresized -- 拷贝部分图像并调整大小
- imagecreate -- 新建一个基于调色板的图像
- imagecreatefromgd2 -- 从 GD2 文件或 URL 新建一图像
- imagecreatefromgd2part -- 从给定的 GD2 文件或 URL 中的部分新建一图像
- imagecreatefromgd -- 从 GD 文件或 URL 新建一图像
- imagecreatefromgif -- 从 GIF 文件或 URL 新建一图像
- imagecreatefromjpeg -- 从 JPEG 文件或 URL 新建一图像
- imagecreatefrompng -- 从 PNG 文件或 URL 新建一图像
- imagecreatefromstring -- 从字符串中的图像流新建一图像
- imagecreatefromwbmp -- 从 WBMP 文件或 URL 新建一图像
- imagecreatefromxbm -- 从 XBM 文件或 URL 新建一图像
- imagecreatefromxpm -- 从 XPM 文件或 URL 新建一图像
- imagecreatetruecolor -- 新建一个真彩色图像
- imagedashedline -- 画一虚线
- imagedestroy -- 销毁一图像
- imageellipse -- 画一个椭圆
- imagefill -- 区域填充
- imagefilledarc -- 画一椭圆弧且填充
- imagefilledellipse -- 画一椭圆并填充
- imagefilledpolygon -- 画一多边形并填充
- imagefilledrectangle -- 画一矩形并填充
- imagefilltoborder -- 区域填充到指定颜色的边界为止
- imagefilter -- 对图像使用过滤器
- imagefontheight -- 取得字体高度
- imagefontwidth -- 取得字体宽度
- imageftbbox -- 给出一个使用 FreeType 2 字体的文本框
- imagefttext -- 使用 FreeType 2 字体将文本写入图像
- imagegammacorrect -- 对 GD 图像应用 gamma 修正
- imagegd2 -- 将 GD2 图像输出到浏览器或文件
- imagegd -- 将 GD 图像输出到浏览器或文件
- imagegif -- 以 GIF 格式将图像输出到浏览器或文件
- imageinterlace -- 激活或禁止隔行扫描
- imageistruecolor -- 检查图像是否为真彩色图像
- imagejpeg -- 以 JPEG 格式将图像输出到浏览器或文件
- imagelayereffect -- 设定 alpha 混色标志以使用绑定的 libgd 分层效果
- imageline -- 画一条线段
- imageloadfont -- 载入一新字体
- imagepalettecopy -- 将调色板从一幅图像拷贝到另一幅
- imagepng -- 以 PNG 格式将图像输出到浏览器或文件
- imagepolygon -- 画一个多边形
- imagepsbbox -- 给出一个使用 PostScript Type1 字体的文本方框
- imagepscopyfont -- 拷贝一个已加载的字体以备更改
- imagepsencodefont -- 改变字体中的字符编码矢量
- imagepsextendfont -- 扩充或精简字体
- imagepsfreefont -- 释放一个 PostScript Type 1 字体所占用的内存
- imagepsloadfont -- 从文件中加载一个 PostScript Type 1 字体
- imagepsslantfont -- 倾斜某字体
- imagepstext -- 用 PostScript Type1 字体把文本字符串画在图像上
- imagerectangle -- 画一个矩形
- imagerotate -- 用给定角度旋转图像
- imagesavealpha -- 设置标记以在保存 PNG 图像时保存完整的 alpha 通道信息（与单一透明色相反）
- imagesetbrush -- 设定画线用的画笔图像
- imagesetpixel -- 画一个单一像素
- imagesetstyle -- 设定画线的风格
- imagesetthickness -- 设定画线的宽度
- imagesettile -- 设定用于填充的贴图
- imagestring -- 水平地画一行字符串
- imagestringup -- 垂直地画一行字符串
- imagesx -- 取得图像宽度
- imagesy -- 取得图像高度
- imagetruecolortopalette -- 将真彩色图像转换为调色板图像
- imagettfbbox -- 取得使用 TrueType 字体的文本的范围
- imagettftext -- 用 TrueType 字体向图像写入文本
- imagetypes -- 返回当前 PHP 版本所支持的图像类型
- imagewbmp -- 以 WBMP 格式将图像输出到浏览器或文件
- imagexbm -- 将 XBM 图像输出到浏览器或文件
- iptcembed -- 将二进制 IPTC 数据嵌入到一幅 JPEG 图像中
- iptcparse -- 将二进制 IPTC http://www.iptc.org/ 块解析为单个标记
- jpeg2wbmp -- 将 JPEG 图像文件转换为 WBMP 图像文件
- png2wbmp -- 将 PNG 图像文件转换为 WBMP 图像文件
add a note
User Contributed Notes
Skyeye
20-Aug-2006 06:04
20-Aug-2006 06:04
Skyeye
19-Aug-2006 07:43
19-Aug-2006 07:43
If you want to make an image through GET with text in several lines, use %0A for line separating, for example:
/image.php?text=Text%20string%0Ain%20several%0Alines.
As also you can make php generated images without other knowing that they are php-made. Simply add the image extension in Apache httpd.conf file:
AddType application/x-httpd-php .php .png
And call image as normal png image:
/somephpautogeneratedimage.png
Of course real .png files will be now treated as php, but if you don`t have png files on your webserver, this won`t be a problem. Or you can use this code for displaying real png images through php code:
<?php
$filename = 'realpngfile.png';
header('Content-type: image/png');
header('Content-length: '.filesize($filename));
readfile($filename);
?>
thomas at tgohome dot com
18-Aug-2006 07:01
18-Aug-2006 07:01
I wrote this script to fetch details about a GIF image. I wanted to use it for avatar details on a CMS system, so I wrote it to return an array of details (instead of having to go through all of the functions)
Without further ado, here the script is:
<?
/*
* Get GIF image data
* Returns an array of data, including GIF image type, and
* the width and height of the image, plus transparent colour
* details and much more.
*
* Copyright 2006 Thomas Oldbury.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
/*
* This function takes one argument, $file, a direct link to the image in
* question. Perhaps in future versions it will get the file from an image
* resource, but for now, it will have to do.
*/
function fetch_gif_data($file) {
/*
* First, we need to get the contents of the file in question, or we print
* a warning using trigger_error().
*/
$file_data = @file_get_contents($file) or trigger_error("File $file does not exist", E_USER_WARNING);
/*
* Now we need to fetch the gif image's version. We'll use strpos to fetch
* gif89a, gif87a or if we don't get that then we will print an error.
*/
$image_type = strpos($file_data, "g");
/*
* Now we check to see wether it is actually a GIF image, as it may not be
* an image and if this is the case, problems could occur.
*/
if($image_type === false) {
trigger_error("File $file is not a gif89a or gif87a compatible image", E_USER_ERROR);
}
/*
* Now, we need to fetch the image type by fetching the text at a certain
* position, using PHP's function substr.
*/
$image_info[version] = substr($file_data, 0, 6);
$image_info[file_reg_version] = substr($file_data, 3, 3);
/*
* Let's get the total number of colours in this image using a special
* piece of code, which fetches all the image's colours.
*/
$im_gif = imagecreatefromgif($file);
$image_info[total_pallete_colours] = imagecolorstotal($im_gif);
/*
* Now, the next thing we need to do is get the width and height of the
* image in question by using imagesx(); and imagesy();
*/
$image_info[width] = imagesx($im_gif);
$image_info[height] = imagesy($im_gif);
/*
* Let's fetch the transparent color of the image, if there is one.
*/
$id = imagecolortransparent($im_gif);
$image_info[transparent_color_id] = $id;
$image_info[transparent_color_values] = imagecolorsforindex($im_gif, $id);
/*
* Now, we return all the data.
*/
return $image_info;
}
/*
* Usage Example:
*/
echo '<pre>';
print_r(fetch_gif_data("hello.gif"));
echo '</pre>';
?>
This script returns something like:
Array
(
[version] => GIF89a
[file_reg_version] => 89a
[total_pallete_colours] => 251
[width] => 100
[height] => 100
[transparent_color_id] => 16
[transparent_color_values] => Array
(
[red] => 0
[green] => 0
[blue] => 0
[alpha] => 127
)
)
Tested on PHP 5.1.2, but should work on older versions.
japidoff isliev nl
12-Aug-2006 06:12
12-Aug-2006 06:12
quite a hassle, but here it is:
gd "Sepia" effect, also called colorisation...
all the math (rgb<->hsl) comes from
http://www.easyrgb.com/math.php
it is NOT optimised, it takes about 10sec for a 500x400 jpeg @2ghz
<?
Function RGB_to_HSL($RGB){
$var_R = $RGB[0] / 255; //Where RGB values = 0 255
$var_G = $RGB[1] / 255;
$var_B = $RGB[2] / 255;
$var_Min = min( $var_R, $var_G, $var_B ); //Min. value of RGB
$var_Max = max( $var_R, $var_G, $var_B ); //Max. value of RGB
$del_Max = $var_Max - $var_Min; //Delta RGB value
$L = ($var_Max + $var_Min) / 2;
if ($del_Max == 0){ //This is a gray, no chroma...
$H = 0; //HSL results = 0 1
$S = 0;
}else{ //Chromatic data...
if ($L < 0.5 ){
$S = $del_Max / ($var_Max + $var_Min);
}else{
$S = $del_Max / (2 - $var_Max - $var_Min);
}
$del_R = ((($var_Max - $var_R) / 6 ) + ($del_Max / 2)) / $del_Max;
$del_G = ((($var_Max - $var_G) / 6 ) + ($del_Max / 2)) / $del_Max;
$del_B = ((($var_Max - $var_B) / 6 ) + ($del_Max / 2)) / $del_Max;
if ($var_R == $var_Max){
$H = $del_B - $del_G;
}elseif ($var_G == $var_Max){
$H = (1 / 3) + $del_R - $del_B;
}elseif($var_B == $var_Max){
$H = (2 / 3) + $del_G - $del_R;
}
if ($H < 0){
$H++;
}
if($H > 1){
$H--;
}
}
Return array($H, $S, $L);
}
Function HSL_to_RGB($HSL){
$H = $HSL[0];
$S = $HSL[1];
$L = $HSL[2];
if ($S == 0){ //HSL values = 0 1
$R = $L * 255; //RGB results = 0 255
$G = $L * 255;
$B = $L * 255;
}else{
if ($L < 0.5){
$var_2 = $L * (1 + $S);
}else{
$var_2 = ($L + $S)-($S * $L);
}
$var_1 = 2 * $L - $var_2;
$R = Round(255 * Hue_2_RGB($var_1, $var_2, $H + (1/3)));
$G = Round(255 * Hue_2_RGB($var_1, $var_2, $H));
$B = Round(255 * Hue_2_RGB($var_1, $var_2, $H - (1/3)));
}
Return array($R, $G, $B);
}
Function Hue_2_RGB($v1, $v2, $vH){ //Function Hue_2_RGB
if ($vH < 0){
$vH++;
}
if ($vH > 1){
$vH--;
}
if ((6 * $vH) < 1){
Return ($v1 + ($v2 - $v1) * 6 * $vH);
}
if ((2 * $vH) < 1){
Return ($v2);
}
if ((3 * $vH) < 2){
return ($v1 + ($v2 - $v1) * ((2 / 3) - $vH) * 6);
}
return ($v1);
}
Function RGB_to_gray($RGB){
$val = round((0.299 * $RGB[0]) + (0.587 * $RGB[1]) + (0.114 * $RGB[2]));
Return array($val, $val, $val);
}
$old_image =imagecreatefromjpeg("./test.jpg");
$old_x = imagesx($old_image);
$old_y = imagesy($old_image);
$new_image = imagecreatetruecolor($old_x, $old_y);
for( $x = 0; $x < $old_x; $x++){
for( $y = 0; $y < $old_y; $y++){
$_rgb = ImageColorAt($old_image, $x, $y); //original color
$RGB[0] = ($_rgb >> 16) & 0xFF; //split 24 bit color in RGB values
$RGB[1] = ($_rgb >> 8) & 0xFF;
$RGB[2] = $_rgb & 0xFF;
$RGB = RGB_to_gray($RGB); //convert to grayscale
$HSL = RGB_to_HSL($RGB); //convert to HSL
$to_hsl = RGB_to_HSL(array(94,38,18)); //set "sepia" color
$HSL[0] = $to_hsl[0]; //change Hue and Saturation values from pixel
$HSL[1] = $to_hsl[1];
$RGB = HSL_to_RGB($HSL); //convert from HSL to RGB
$_rgb = intval(($RGB[2]) + ($RGB[1] << 8) + ($RGB[0] << 16)); //merge from RGB to 24 bit
imagesetpixel($new_image, $x, $y, $_rgb); //draw pixel in new image
}
}
header('Content-Control: cache');
header('Content-type: image/jpeg');
imagejpeg($new_image);
sampathperera at hotmail dot com - Sri Lanka
21-Jul-2006 01:04
21-Jul-2006 01:04
I have used following function to generate Security Images to authenticate users are real humans. Need to have GD graphic library with FreeType enabled.
Used a gif file as background, put random text on it & creates a new gif file as output.
<?php
function createImage(){
// creates the images, writes the file
$fileRand = md5(rand(100000,999999));
$string_a = array("A","B","C","D","E","F","G","H","J","K",
"L","M","N","P","R","S","T","U","V","W","X","Y","Z",
"2","3","4","5","6","7","8","9");
$keys = array_rand($string_a, 6);
foreach($keys as $n=>$v){
$string .= $string_a[$v];
}
$backgroundimage = "security_background.gif";
$im=imagecreatefromgif($backgroundimage);
$colour = imagecolorallocate($im, rand(0,255), rand(0,255), rand(0,255));
$font = 'Arial';
$angle = rand(-5,5);
// Add the text
imagettftext($im, 16, $angle, 15, 25, $colour, $font, $string);
$outfile= "$fileRand.gif";
imagegif($im,$outfile);
return $outfile;
}
echo "<IMG SRC=".createImage()." name=secimg>";
?>
g8z at yahoo dot com
20-Jul-2006 04:39
20-Jul-2006 04:39
<?php
/**
chunk_image breaks an image into roughly equal chunks horizontally (which are returned in an array of image resources)
parameters:
$image = image resource to work on
$chunks = number of chunks to break the image into
Courtesy of the $5 Script Achive: http://www.tufat.com
**/
function chunk_image_horizontally ($image, $chunks = 1)
{
$image_width = imagesx($image);
$image_height = imagesy($image);
// calculate required chunk size
$chunk_size = round($image_width / $chunks);
// do all but the last chunk
for ($current_chunk = 1; $current_chunk < $chunks; $current_chunk++) {
// create image resource to store chunk
$chunk_images[$current_chunk - 1] = imagecreate($chunk_size, $image_height);
// copy chunk to chunk images array
imagecopy($chunk_images[$current_chunk - 1], $image, 1, 1, $chunk_size * ($current_chunk - 1) + 1 , 1, $chunk_size, $image_height);
}
// get last chunk
$chunk_images[$chunks - 1] = imagecreate($chunk_size, $image_height);
imagecopy($chunk_images[$chunks - 1], $image, 1, 1, $chunk_size * ($chunks - 1) + 1 , 1, $image_width, $image_height);
// return array
return $chunk_images;
}
//Example:
// read in test.jpg, and break it into 4 chunks using our function
$in_image = imagecreatefromjpeg('./image.jpg');
$images = chunk_image_horizontally($in_image, 4);
$count = 0;
// save chunks to files
foreach ($images as $image) {
$count++;
imagejpeg($image, './test_chunk'.$count.'.jpg');
}
?>
g8z at yahoo dot com
20-Jul-2006 04:36
20-Jul-2006 04:36
<?php
/**
change_color replaces $old_color with $new_color. $threshold allows you to specify how far away from the specified color a pixel can be and still be considered a match. $old_color and $new_color must be decimal color values.
Courtesy of the $5 Script Achive: http://www.tufat.com
*/
function change_color($image, $old_color, $new_color, $threshold = 15)
{
$image_width = imagesx($image);
$image_height = imagesy($image);
// iterate through x axis
for ($x = 0; $x < $image_width; $x++) {
// iterate through y axis
for ($y = 0; $y < $image_height; $y++) {
// look at current pixel
$pixel_color = imagecolorat($image, $x, $y);
if (($pixel_color <= $old_color + $threshold) && ($pixel_color >= $old_color - $threshold)) {
// replace with new color
imagesetpixel($image, $x, $y, $new_color);
}
}
}
}
// EXAMPLE:
// convert all red in the image to green
$image = imagecreatefromjpeg('./test.jpg');
$red_rbg = 16646146;
$green_rbg = 65341;
change_color($image, $red_rbg, $green_rbg, 15);
imagejpeg($image, './test_changed.jpg');
?>
php at synvb dot com
22-Apr-2006 11:19
22-Apr-2006 11:19
Here is a single-function to flip, based on the one below.
<?php
function flipImage($image, $vertical, $horizontal) {
$w = imagesx($image);
$h = imagesy($image);
if (!$vertical && !$horizontal) return $image;
$flipped = imagecreatetruecolor($w, $h);
if ($vertical) {
for ($y=0; $y<$h; $y++) {
imagecopy($flipped, $image, 0, $y, 0, $h - $y - 1, $w, 1);
}
}
if ($horizontal) {
if ($vertical) {
$image = $flipped;
$flipped = imagecreatetruecolor($w, $h);
}
for ($x=0; $x<$w; $x++) {
imagecopy($flipped, $image, $x, 0, $w - $x - 1, 0, 1, $h);
}
}
return $flipped;
}
?>
shd at earthling dot net
28-Mar-2006 08:44
28-Mar-2006 08:44
If you happen to need a way to output a Windows BMP file (e.g. when using the PEAR ExcelWriter), feel free to use the following code:
<?php
function imagebmp ($im, $fn = false)
{
if (!$im) return false;
if ($fn === false) $fn = 'php://output';
$f = fopen ($fn, "w");
if (!$f) return false;
//Image dimensions
$biWidth = imagesx ($im);
$biHeight = imagesy ($im);
$biBPLine = $biWidth * 3;
$biStride = ($biBPLine + 3) & ~3;
$biSizeImage = $biStride * $biHeight;
$bfOffBits = 54;
$bfSize = $bfOffBits + $biSizeImage;
//BITMAPFILEHEADER
fwrite ($f, 'BM', 2);
fwrite ($f, pack ('VvvV', $bfSize, 0, 0, $bfOffBits));
//BITMAPINFO (BITMAPINFOHEADER)
fwrite ($f, pack ('VVVvvVVVVVV', 40, $biWidth, $biHeight, 1, 24, 0, $biSizeImage, 0, 0, 0, 0));
$numpad = $biStride - $biBPLine;
for ($y = $biHeight - 1; $y >= 0; --$y)
{
for ($x = 0; $x < $biWidth; ++$x)
{
$col = imagecolorat ($im, $x, $y);
fwrite ($f, pack ('V', $col), 3);
}
for ($i = 0; $i < $numpad; ++$i)
fwrite ($f, pack ('C', 0));
}
fclose ($f);
return true;
}
?>
It works the same way as regular imagejpeg/imagepng do and only supports GD2.0 true colour bitmaps (which is what's required by ExcelWriter).
felipensp at gmail dot com
13-Mar-2006 01:17
13-Mar-2006 01:17
Representation decimal of a color in hexadecimal for use on functions of library GD.
<?php
// Representation hexadecimal
$var = '#FFFFFF';
function getRgbFromGd($color_hex) {
return array_map('hexdec', explode('|', wordwrap(substr($color_hex, 1), 2, '|', 1)));
}
print_r(getRgbFromGd($var));
// Output: Array ( [0] => 255 [1] => 255 [2] => 255 )
?>
andrew dot barlow at gmail dot com
01-Mar-2006 01:47
01-Mar-2006 01:47
To create a simple transparent gif with black text with any TrueType Font...
Simple put this script into a PHP file and call it with the usual IMG tag.
You can also specify the font size for the IMG tag too.
Change the $font to your own font and upload it to the same directory as this script.
<?php
// Set the content-type
header("Content-type: image/gif");
$fontsize = 18;
if(@$_GET['fontsize']) {
$fontsize = $_GET['fontsize'];
}
$font = 'yourcustomfont.ttf';
$text = @$_GET['text'];
// Create the image
$size = imagettfbbox($fontsize, 0, $font, $text);
$width = $size[2] + $size[0] + 8;
$height = abs($size[1]) + abs($size[7]);
$im = imagecreate($width, $height);
$colourBlack = imagecolorallocate($im, 255, 255, 255);
imagecolortransparent($im, $colourBlack);
// Create some colors
$white = imagecolorallocate($im, 255, 255, 255);
$black = imagecolorallocate($im, 0, 0, 0);
// Add the text
imagefttext($im, $fontsize, 0, 0, abs($size[5]), $black, $font, $text);
// Using imagepng() results in clearer text compared with
imagegif($im);
imagedestroy($im);
?>
relsqui at chiliahedron dot com
18-Feb-2006 03:14
18-Feb-2006 03:14
<?php
// This is a correction to the image-flipping function I posted previously.
// The bitwise ands (&) were incorrectly written as logical ands (&&).
// Needless to say, that breaks the function in obnoxious--if amusing--ways.
define("VERTICAL", 1);
define("HORIZONTAL", 2);
function imageflip($image, $mode) {
$w = imagesx($image);
$h = imagesy($image);
$flipped = imagecreate($w, $h);
if ($mode & VERTICAL) {
for ($y = 0; $y < $h; $y++) {
imagecopy($flipped, $image, 0, $y, 0, $h - $y - 1, $w, 1);
}
}
if ($mode & HORIZONTAL) {
for ($x = 0; $x < $w; $x++) {
imagecopy($flipped, $image, $x, 0, $w - $x - 1, 0, 1, $h);
}
}
return $flipped;
}
?>
relsqui at chiliahedron dot com
14-Feb-2006 07:22
14-Feb-2006 07:22
On the offchance someone else should need one, here's a function you can use to randomly "mix" two colors, resulting in a "child" color with components of both. You might use it to come up with ideas for a color scheme, for example; the image section seemed as good a place for it as any.
<?php
// $mom and $dad should be integers, quite possibly the output of hexdec().
// Similarly, the return value $child will be an integer suitable for feeding to dechex().
breed_colors($mom, $dad) {
do { $maskhex .= rand()&1 ? "f" : "0"; } while (strlen($maskhex) < 6);
$mask = hexdec($maskhex);
$inversemask = $mask ^ 16777215;
$child = ($mom & $mask) | ($dad & $inversemask);
return $child;
}
// For example:
breed_colors(hexdec("012345"), hexdec("6789ab"));
// Let's say the random mask was ff0f0f.
// The inverse mask is therefore 00f0f0.
// $mom & $mask == 010305.
// $dad & $inversemask == 0080a0.
// Those two |ed together make 0183a5, which combines the traits of the parents into one $child.
?>
jan at anh dot sk
15-Jan-2006 08:03
15-Jan-2006 08:03
When outputing an image from a script to a browser, use header("Content-Length: XYZ") together with Content-Type header. This avoids problems rendering-displaying the image with some browsers (f.i. MSIE) - fixes random image cutting of image bottom parts. Image from cache example:
<?php
$cache_file = "imagecache/{$ID}.img";
header("Content-Type: image/jpeg");
header("Content-Length: ".filesize($cache_file));
$cache = fopen($cache_file,"r");
fpassthru($cache);
fclose($cache);
exit;
?>
Problem observed @ Linux, Apache 2.0, PHP 4.3.10
matrixhasu at gmail dot com
14-Jan-2006 07:44
14-Jan-2006 07:44
Sorry,
a little bug found in the previous note: what was
<?php
for ($i=0; $i<count($Values); $i++){
$graphValues[$i] =
($Values[$i] - $min*(1-2*$graphspacing)) *
(($imgHeight*(1-