tfl at netcabo dot pt / 18-Aug-2005 03:48

IE doesn't show TIFF files and standard PHP distribution doesn't support converting to/from TIFF.

ImageMagick (http://www.imagemagick.org/script/index.php) is a free software that can read, convert and write images in a large variety of formats. For Windows users it includes a PHP extension php_magickwand_st.dll (and yes, it runs under PHP 5.0.4).

When converting from TIFF to JPEG, you must also convert from CMYK color space to RGB color space as IE can't show CMYK JPGs either. Please note:
-TIFF files may have RGB or CMYK color space
-JPEG files may have RGB or CMYK color space

Here are example functions using ImageMagick extension:
- convert TIFF to JPEG file formats
- convert CMIK to RGB color space
- set image resolution to 300 DPIs (doesn't change image size in pixels)

<?php function cmyk2rgb($file) { $mgck_wnd = NewMagickWand(); MagickReadImage($mgck_wnd, $file); $img_colspc = MagickGetImageColorspace($mgck_wnd); if ($img_colspc == MW_CMYKColorspace) { echo "$file was in CMYK format<br />"; MagickSetImageColorspace($mgck_wnd, MW_RGBColorspace); } MagickWriteImage($mgck_wnd, str_replace('.', '-rgb.', $file)); } function tiff2jpg($file) { $mgck_wnd = NewMagickWand(); MagickReadImage($mgck_wnd, $file); $img_colspc = MagickGetImageColorspace($mgck_wnd); if ($img_colspc == MW_CMYKColorspace) { echo "$file was in CMYK format<br />"; MagickSetImageColorspace($mgck_wnd, MW_RGBColorspace); } MagickSetImageFormat($mgck_wnd, 'JPG' ); MagickWriteImage($mgck_wnd, str_replace('.tif', '.jpg', $file)); } function to300dpi($file) { $mgck_wnd = NewMagickWand(); MagickReadImage($mgck_wnd, $file); $img_units = MagickGetImageUnits($mgck_wnd); switch ($img_units) { case MW_UndefinedResolution: $units= 'undefined'; break; case MW_PixelsPerInchResolution: $units= 'PPI'; break; case MW_PixelsPerCentimeterResolution: $units= 'PPcm'; break; } list($x_res, $y_res) = MagickGetImageResolution($mgck_wnd); echo "$file<br /> x_res=$x_res $units - y_res=$y_res $units<br />"; if($x_res == 300 && $y_res == 300 && $img_units == MW_PixelsPerInchResolution) {return; } MagickSetImageResolution($mgck_wnd, 300 , 300); MagickSetImageUnits($mgck_wnd, MW_PixelsPerInchResolution); MagickWriteImage($mgck_wnd, str_replace('.', '-300.', $file)); } $file='photos/test-cmyk.tif'; //this is a TIFF file in CMYK format with a 96 DPI resolution cmyk2rgb($file); $file = str_replace('.', '-rgb.', $file); to300dpi($file); $file = str_replace('.', '-300.', $file); tiff2jpg($file); $file = str_replace('.tif', '.jpg', $file); to300dpi($file); /* no file name changes as ImageMagick reports 300 DPIs $file = str_replace('.', '-300.', $file); */ list($width, $height, $type, $attr) = getimagesize($file); $width = $width/3; $height = $height/3; echo "<img src=\"http://localhost/$file\" width=\"$width\" height=\"$height\" alt=\"getimagesize() example\" />"; echo "<br />$file => width=$width - height=$height - type=$type - attr=$attr<br /><br />"; $file='photos/test-rgb.tif'; //this is a TIFF file in RGB format with a 96 DPI resolution cmyk2rgb($file); $file = str_replace('.', '-rgb.', $file); to300dpi($file); $file = str_replace('.', '-300.', $file); tiff2jpg($file); $file = str_replace('.tif', '.jpg', $file); to300dpi($file); /* no file name changes as ImageMagick reports 300 DPIs $file = str_replace('.', '-300.', $file); */ list($width, $height, $type, $attr) = getimagesize($file); $width = $width/3; $height = $height/3; echo "<img src=\"http://localhost/$file\" width=\"$width\" height=\"$height\" alt=\"getimagesize() example\" />"; echo "<br />$file => width=$width - height=$height - type=$type - attr=$attr<br /><br />"; ?>