PDF Boxes : mediabox, cropbox, bleedbox, trimbox, artbox

An EPS has only a single BoundingBox but a PDF contains a MediaBox, CropBox, BleedBox, TrimBox and ArtBox.

When opening a PDF, scribus requests which of these boxes content the user wish to import.

For example, for an advertisement,
 * ArtBox is the content of the ad;
 * TrimBox is the size that an application like Scribus should use to place the ad;
 * BleedBox is the size that applications like Scribus should clip to;
 * CropBox is the size for proofing the ad for viewers but is not supposed to be used by applications like Scribus;
 * MediaBox is for complete pages including items that will be physically trimmed from the final product like crop marks, registration marks, slugs, etc.



Here are a few links to pages illustrating the boxes with images.
 * http://www.plda.net/en/Examples/UserGuide/PageBoxes.aspx
 * https://acrobatusers.com/tutorials/finding-page-boundaries

For a detailed description of these boxes, see http://www.prepressure.com/pdf/basics/page-boxes, or the ISO definition of these boxes that follow, further down in that page.

Some viewers like "gv" have an option to let you override the displayed area.

The poppler package has the capability also, for example, pdftops crops to the CropBox by default but has a -nocrop option to use the MediaBox instead.

On Linux, you can check the values with pdfinfo in the poppler package with the -box option.

$ pdfinfo -box 20185846-crop.pdf Producer:      Acrobat Distiller 3.0 for Power Macintosh CreationDate:  Thu Dec 11 16:40:22 2003 ModDate:       Fri Dec 12 13:09:10 2003 ... Page size:     415.79 x 1009.81 pts Page rot:      0 MediaBox:          0.00     0.00   432.00  1152.00 CropBox:           7.89    16.19   423.68  1026.00 BleedBox:          7.89    16.19   423.68  1026.00 TrimBox:           7.89    16.19   423.68  1026.00 ArtBox:            7.89    16.19   423.68  1026.00 File size:     464073 bytes Optimized:     yes PDF version:   1.4

PDF specification ISO 32000-1:2008 as published by Adobe
Source : Adobe ISO 32000-1:2008 Specification

14.11.2.1 General
A PDF page may be prepared either for a finished medium, such as a sheet of paper, or as part of a prepress process in which the content of the page is placed on an intermediate medium, such as film or an imposed reproduction plate. In the latter case, it is important to distinguish between the intermediate page and the finished page. The intermediate page may often include additional production-related content, such as bleeds or printer marks, that falls outside the boundaries of the finished page. To handle such cases, a PDF page maydefine as many as five separate boundaries to control various aspects of the imaging process:

The media box defines the boundaries of the physical medium on which the page is to be printed. It may include any extended area surrounding the finished page for bleed, printing marks, or other such purposes. It may also include areas close to the edges of the medium that cannot be marked because of physical limitations of the output device. Content falling outside this boundary may safely be discarded without affecting the meaning of the PDF file.

The crop box defines the region to which the contents of the page shall be clipped (cropped) when displayed or printed. Unlike the other boxes, the crop box has no defined meaning in terms of physical page geometry or intended use; it merely imposes clipping on the page contents. However, in the absence of additional information (such as imposition instructions specified in a JDF or PJTF job ticket), the crop box determines how the page’s contents shall be positioned on the output medium. The default value is the page’s media box.

The bleed box (PDF 1.3) defines the region to which the contents of the page shall be clipped when output in a production environment. This may include any extra bleed area needed to accommodate the physical limitations of cutting, folding, and trimming equipment. The actual printed page may include printing marks that fall outside the bleed box. The default value is the page’s crop box.

The trim box (PDF 1.3) defines the intended dimensions of the finished page after trimming. It may be smaller than the media box to allow for production-related content, such as printing instructions, cut marks, or colour bars. The default value is the page’s crop box.

The art box (PDF 1.3) defines the extent of the page’s meaningful content (including potential white space) as intended by the page’s creator. The default value is the page’s crop box.

The page object dictionary specifies these boundaries in the MediaBox, CropBox, BleedBox, TrimBox, and ArtBox entries, respectively (see Table 30). All of them are rectangles expressed in default user space units. The crop, bleed, trim, and art boxes shall not ordinarily extend beyond the boundaries of the media box. If they do, they are effectively reduced to their intersection with the media box. Figure 86 illustrates the relationships among these boundaries. (The crop box is not shown in the figure because it has no defined relationship with any of the other boundaries.)