FLIGHTCHECK® may report a problem with an image that can be corrected by returning to the document's application and editing or modifying the picture box containing the image.
Fill "None"/Clipping Path
When an image resides in a QuarkXPress® picture box which is using the special transparency color "None", sometimes QuarkXPress® will calculate the white space surrounding the image and create a "clip" which is a generally crude and low resolution path and often causes the image to printed with "jagged edges". The solution is to either change the background color to either White (or 0% Black) or to return to the imaging application and apply an actual clipping path. Note that vector drawings, such as Illustrator images, can be excluded from this concern, but rasterized TIFF or EPS images which contain white should cause you to sit up and pay attention.
Box Rotation/Skew
A rotated or skewed picture containing an image can alter or distort the quality of the image when printed. This can also add to processing time and it is therefore recommended that you return the image to the application which created it, perhaps as far back as to rescan a photo, and to rotate or skew the image in the imaging application so it can be reimported back into the document upright.
Image Scale
Scaling a rasterized pixel-based image is by far the most serious picture box attribute to contend with as it becomes an extremely critical factor in determining the output quality. When you scale an image, its resolution (dots per inch) will change. If an image is scaled too low, the dots compress and the resolution increases. If the image is scaled way up, the dots spread apart and the quality is lost. When an image is scaled, the new DPI is called the "effective resolution" and this value needs to be compared with the output line screen in order to determine whether or not the scaling will be acceptable or not, or if the image needs to be returned to the imaging application, or rescanned, in order to place the image in the document at 100%.
Image Rotation/Skew
A rotated or skewed image within in a picture box can cause a distortion or alteration of the quality of the image when printed. This can also add to processing time and it is therefore recommended that you return the image to the application which created it and rotate or skew the image so it can be reimported back into the picture box upright.
Horizontal/Vertical Flip
FLIGHTCHECK® will alert you when the contents of a picture box has been flipped horizontally or vertically.
Image Stlyes/Contrast
Most applications allow you to colorize Black & White 1-bit images, or to apply a contrast to grayscale images. These attributes are called "picture styles". However, sometimes this information is ignored when sent to certain printers, or lost during an OPI hi-res swap. In this case, you may need to return the image to the application which created it to give it the desired color or contrast.
Picture Trap
FLIGHTCHECK® will detect when an image has been set for Picture Trap. It is generally recommended that all trapping values should be left to the professionals at the Service Bureau.
Halftone Screen
FLIGHTCHECK® can be asked to inform you when an image contains an internal Halftone Screen, in which case you may need to edit the image within the imaging application to correct this situation.
Transfer Function
FLIGHTCHECK® can be asked to inform you when an image contains a Transfer Function. This is an internal calculation which will alter the values of the pixel data during printing. Therefore, you may need to edit the image within the imaging application to correct this situation.
Channels
FLIGHTCHECK® will alert you when the image contains additional channels. Some printing devices cannot support the extra data and will cause the job to abort. You may need to return to the imaging application and remove the extra channels.
Layers
FLIGHTCHECK® will also alert you when the image is comprised of multiple layers. Some printing devices cannot handle layered images, in which case you may need to return to the imaging application and remove the layers (called "flattening" the file).