Pixels, PPI and print size: How big can the image be printed?
When a bitmap is not resampled, the printed width in inches is equal to the number of horizontal pixels divided by the PPI; centimeters are multiplied by 2.54. The required PPI is determined by the purpose and producer. Modifying the resolution tag alone will not increase the details of the original image.
What do pixels, PPI and centimeters describe?
Number of pixels describes how many points the bitmap grid has, PPI describes how many image pixels are arranged per inch, and centimeters describe the actual output size. The DPI of the printing device and the PPI of the image are different indicators, and you should be clear about which one you are talking about when communicating.
Adobe Photoshop's image size and resolution description distinguishes between resampling and output resizing. Note the actual number of pixels before calculating the size, and then see if the current settings have added or deleted pixels.
How to estimate the actual output width of an image?
For example, if the width is 2400 pixels and arranged at 300 PPI, the width is 2400 ÷ 300 = 8 inches, about 20.32 cm. If the same pixels are arranged to 40.64 cm wide, the corresponding density is about 150 PPI.
This example is used to illustrate the mathematical relationship and not all printing must use 300 PPI. The viewing distance, product, process and image content are different and should be judged according to the manufacturer's requirements rather than taking a numerical value as a guarantee of clarity.
- Record the real width and height pixels of the picture and do not use the chat thumbnail size.
- Confirm target centimeter size and desired image density with the producer.
- Estimated centimeter dimensions in pixels ÷ PPI × 2.54.
- Check important details in expected sizes and confirm proofs.
Would changing 72 PPI to 300 PPI make it clearer?
When there is no resampling and the number of pixels remains unchanged, adjusting the label only changes the relationship between the output size and density, and does not increase details out of thin air. Using resampling to increase pixels is not equivalent to retrieving the missing original information.
Converting images to SVG is to trace the outline of the graphic, which is suitable for logos or patterns that need to be edited. For photos or small text, the original image information and tracing results should still be judged, and the check cannot be skipped just because the output suffix changes.
SVG format basis and reference materials
SVG can contain both vector shapes, images, and text. Therefore, a file name ending in .svg does not alone prove that the original image has been converted to an editable path.W3C SVG 2 Specification: SVG Graphics Objectdescribes these object types.
The above information is used to describe the file format. The upload restrictions, membership requirements, results saving and editing capabilities of this site are subject to the page description and actual functions.