Bitmap images (also known as raster images) are made up of pixels in a grid. Pixels are picture elements; tiny dots of individual color that make up what you see on your screen.
All these tiny dots of color come together to form the images you see. The typical computer monitor has 72 or 96 pixels per inch, depending on your monitor and screen settings.
Common bitmap formats include :
- JPEG, JPG
- PICT (Macintosh)
- PSD (Adobe Photoshop)
All scanned images are bitmaps, and all images from digital cameras are bitmaps.
Converting between bitmap formats is generally as simple as opening the image to be converted and using your software's Save As... command to save it in any other bitmap format supported by your software.
Bitmap images in general do not inherently support transparency. A couple of specific formats--namely GIF and PNG--support transparency. In addition, most image editing programs support transparency, but only when the image is saved in the software program's native format. A common misconception is that the transparent areas in an image will remain transparent when an image is saved to another format or copied and pasted into another program .
Points About Bitmap Images :
- pixels in a grid
- resolution dependent
- resizing reduces quality
- easily converted
- restricted to rectangle
- minimal support for transparency
Facts About Vector Images :
Vector images are made up of many individual, scalable objects. These objects are defined by mathematical equations rather than pixels, so they always render at the highest quality. Objects may consist of lines, curves, and shapes with editable attributes such as color, fill, and outline. Changing the attributes of a vector object does not effect the object itself. You can freely change any number of object attributes without destroying the basic object. An object can be modified not only by changing its attributes, but also by shaping and transforming it using nodes and control handles.
Because they're scalable, vector-based images are resolution independent. You can increase and decrease the size of vector images to any degree and your lines will remain crisp and sharp, both on screen and in print. Fonts are a type of vector object.
Another advantage of vector images is that they're not restricted to a rectangular shape like bitmaps. Vector objects can be placed over other objects, and the object below will show through. See the example images on this page. The vector circle and bitmap circle appear to be exactly the same when seen on a white background. But when you place the bitmap circle over another color, it has a rectangular box around it, from the white pixels in the image.
Vector images have many advantages, but the primary disadvantage is that they're unsuitable for producing photo-realistic imagery. Vector images are usually made up of solid areas of color or gradients, but they cannot depict the continuous subtle tones of a photograph. That's why most of the vector images you see tend to have a cartoon-like appearance. Even so, vector graphics are continually becoming more advanced, and we can do a lot more with vector drawings now than we could just a few years ago. Today's vector tools allow you to apply bitmapped textures to objects giving them a photorealistic appearance, and you can now create soft blends, transparency, and shading that once was difficult to achieve in vector drawing programs.
vector images can, quite easily, be converted to bitmaps. This process is called rasterizing. When you convert a vector image to a bitmap, you can specify the output resolution of the final bitmap for whatever size you need. It's always important to save a copy of your original vector artwork in its native format before converting it to a bitmap; once it has been converted to a bitmap, the image loses all the wonderful qualities it had in its vector state. If you convert a vector to a bitmap at a size of 100 x 100 pixels and then decide you need the image to be larger, you'll need to go back to the original vector file and export the image again. Also keep in mind that opening a vector image in a bitmap editing program usually destroys the vector qualities of the image and converts it to raster data.
Common vector formats include :
- AI (Adobe Illustrator)
- CDR (CorelDRAW)
- CMX (Corel Exchange)
- CGM Computer Graphics Metafile
- DXF CAD
- WMF Windows Metafile
If you are working with mainly solid color objects, manipulated text or many small objects, the clear answer is that a vector program will save you time. If you are working with complicated drop shadows, or other 3D effects, texture or photographs, raster is the correct choice.
Advantages of Raster to Vector :
- Cost effective hand-drawn conversions
- Quick turn around, even on large jobs
- High accuracy:
- Accurate layer information
- Accurate text (editable)
- Accurate line types (editable)
- Associative dimensions (adjustable)
- Associative hatch patterns (editable)
- Symbols & blocks of standard components
- Title blocks (as per scale)
- Output is in a fully editable vector format
Besides the above, from a 3-D perspective, rendering shadows is also much more realistic with vector graphics, as shadows can be abstracted into the rays of light which form them. This allows for photo realistic images and renderings.
A vectorized image has no jaggedness, no loss in detail and can be printed at any resolution or any size. The image can be scaled up or down without any loss in quality. Moreover, the archive of the artwork can be used for manuals, brochures, newspapers and a host of other areas.
- Raster to vector conversion of Technical Drawings (AEC)
- Raster to vector conversion of House plans
- Raster to vector conversion of GIS (CAD)
- Raster to vector conversion of Blueprints
- Raster to vector conversion of Logos
- Vectorization for website applications
- Vectorization for Graphic Design purposes