Multi-image Stitcher and Long Screenshot Combiner
Combine 2–20 local images vertically or horizontally, reorder them, adjust gaps and borders, equalize width or height and save one PNG.
About this multi-image stitcher and long screenshot combiner
Combine 2–20 local images vertically or horizontally, reorder them, adjust gaps and borders, equalize width or height and save one PNG Processes media assets directly in the browser using HTML5 Canvas and WebAssembly decoders, ensuring zero file uploads.
Image processing & canvas pipeline
Performs high-precision 2D affine geometric transformations, aspect-ratio scaling, and rectangular cropping on raster images. Algorithms calculate proportional scaling factors preserving aspect ratios (e.g. 16:9, 4:3, 1:1, 9:16), implement bilinear interpolation for smooth downsampling, and execute 90-degree orthogonal rotations and horizontal/vertical reflections without interpolation loss. Generates multi-resolution icon packages for iOS (Apple Touch Icon), Android (Adaptive Icons), and desktop favicons.
Worked image transformation example
Scenario: Join two 3×2 test PNGs horizontally in selection order.
Sample input:
Processing: Canvas allocates 6×2, draws A at x=0 and B at x=3.
Illustrative output:
Resolution, dimension & memory limits
Operational constraints and validation boundaries: PNG/JPEG/WebP only; each file smaller than 30 MB, combined at most 100 MB, 2–20 files. Each source side must be below 16384px, at most 16,777,216 pixels each and 33,554,432 decoded source pixels in total. Output width and height must both be below 16384px and total at most 16,777,216 pixels; excess is rejected, not cropped. Gap/border integer 0–256px; background 3/6-digit HEX or transparent. Scaling uses browser interpolation; upscaling cannot recover detail. No overlap detection, panorama blending, remote URLs, SVG, animation preservation, metadata retention or color-profile certification. Large compressed images still need browser decoding memory; near-limit memory stress, physical touch and other browsers remain unverified.
Multi-image Stitcher and Long Screenshot Combiner image operations execute in client memory via HTML5 Canvas and browser decoders. Inspect output previews before replacing source assets.
In-memory image processing boundary
File buffers and document assets in Multi-image Stitcher and Long Screenshot Combiner are processed in-memory via local browser APIs with zero file uploads to CZOA servers.
Image format & W3C Canvas standards
W3C Canvas 2D context specifications and standard image container formats:
- WHATWG Canvas 2D
- PNG (ISO/IEC 15948)
Multi-image Stitcher and Long Screenshot Combiner verification · Audit standards
How to use it
- Enter, paste, or select your input data into the Multi-image Stitcher and Long Screenshot Combiner workspace controls.
Frequently asked questions
How are ordering, scaling and output limits applied?+
Operational requirements for "How are ordering, scaling and output limits applied?" are verified in local memory during execution of Multi-image Stitcher and Long Screenshot Combiner.
Which controls and input requirements are available?+
Select 2–20 images together. Drag a row onto another row or use Move earlier/later. Vertical equal sizing uses the widest source width; horizontal uses the tallest source height, preserving aspect ratios and rounding to whole pixels. Original sizing aligns images at the top/left. Set gaps, an outer border and a HEX or transparent background; preview updates immediately. Example: red 4×2, blue 6×4, green 2×6, vertical equal sizing with gap 3 and border 2 gives 10×35px. The original two-image horizontal tool remains below.
What boundaries affect the result?+
PNG/JPEG/WebP only; each file smaller than 30 MB, combined at most 100 MB, 2–20 files.
What does stitching red and blue 3×2 images produce?+
Original two-image horizontal stitcher: Stitch a red 3×2 image beside a blue 3×2 image. The resulting PNG is 6×2 with the expected red left pixels and blue right pixels; this does not establish broader privacy behavior.